(1) The Creator (different from Brahm). One of the three manifestations of Param Brahm, who creates the world. It is said that Brahmaa was born from a lotus stem which came out from Vishnu's navel. He lives in Vairaaj city and his court's name is Kaantimatee.
(Padm Puraan, p 43)
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(2) God as Creator. One of the three aspects of God, Trinity - Brahmaa, Vishnu and Shiv. Brahmaa the Creator, Vishnu the Preserver and Shiv the Destroyer. Brahmaa never gained the prominence that Vishnu and Shiv have received in the Hindoo worship. As of 1996 AD, there were only two temples of Brahmaa - one in Pushakar Jee in Raajsthaan, India and the other one in Las Vegas, Nevada, USA.

Strangely enough the name Brahmaa is not found in Ved, although Vishnu and Shiv exist very importantly, especially Shiv as Rudra. One day of Brahmaa is said to consist of 2,160,000,000 human years At the end of his day, the Universe undergoes Pralaya (dissolution). It is created again after he wakes up after the night of the same length.

An absurd story is given in the MBH that a lotus stalk grew from the navel of Vishnu and Brahmaa appeared sitting on that lotus. Another story in relation to Brahmaa is this that he gave such Var to enemies of God, such as Bali, that they used it against good people. Among the three goddesses, Durga, Lakshmee and Saraswatee, the first one is the consort of Shiv, the second is of Vishnu, but the third one is not clear. For the sake of convenience, Saraswatee has been declared as the consort of Brahmaa.
[Aangiras, p 255]
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(3) One of the four people to perform a Yagya, and when a Yagya is completed by these four people, it is called Chaaturhotra - (1) Hotaa (chants Rig Ved Mantra), (2) Adhwaryu (chants Yajur Ved Mantra), (3) Udgaataa (chants Saam Ved Mantra); and (4) Brahmaa (chants Atharv Ved Mantra).

Brahmaa's 108 Names and 108 Dwelling Places on Earth

He lives in all these places with these names at all the three Sandhyaa times -

[Padm Puraan, p 112]

Brahmaa's Day
The Vishnu Puraan states that at the end of the daytime period of Brahma, a dreadful drought occurs that lasts 100 years, and all the waters are dried up. The Sun changes into seven Suns, and the three worlds (Bhoor Lok or Earth, Bhuvar Lok or the lowest heaven, and Swar Lok or the next higher Heaven) and the underworlds are burned bare of life. The inhabitants of Bhuvar Lok and Swarg Lok flee to the next higher Heaven, Mahar Lok, to escape the heat; and then to the next higher heaven, Jan Lok.

The destruction that takes place at the end of a daytime of Brahma is referred to as Naimittik Pralaya, which is incidental or occasional. The characteristic of this destruction is that the three worlds continue to exist but are made uninhabitable. The souls of individuals also continue to exist to be reincarnated in the next daytime of Brahmaa.

Brahmaa's Age
Thus Bhagvaan Soorya, Swaamee of all planets, constellations, and stars revolve in 12 Rashi (Signs), from Paramaanu to Samvatsar time. According to Soorya, Brihaspati, Savan, Chandramaa and Nakshatra, this time period is called Samvatsar (according to Soorya), Parivatsar (according to Brihaspati), Idaavatsar (according to Savan), Anuvatsar (according to Chandramaa) and Vatsar (according to Nakshatra). Thus this Soorya is the cause of creating five types of years.

Yug = There are 4 Yug, Sat, Tretaa, Dwaapar, and Kali. They are in the proportion of 4:3:2:1 thousands Divine-years. Thus :
  Sat ......... 4,000 Divine-years + 800 Divine years of Sandhyaa and Sandhyaansh)
  Tretaa ..... 3,000 Divine-years + 600 Divine years of Sandhyaa and Sandhyaansh)
  Dwaapar ... 2,000 Divine-years + 400 Divine years of Sandhyaa and Sandhyaansh)
  Kali .......... 1,000 Divine-years  + 200 Divine years of Sandhyaa and Sandhyaansh)

In whatever Yug whatever thousand years are, its double the years in hundreds are in its Sandhyaa and Sandhyaansh, such as Kali Yug has 1,000 divine years so its double means 2, and in hundreds i.e. 200 years should be the Sandhyaa and Sandhyaansh. The beginning of Yug is Sandhyaa and the end of the Yug is Sandhyaansh. So their duration is in hundred years and in between them is the Yug. Thus their total time period is:

  Sat ......... 4,800 Divine-years x 360* = 1,728,000 Human-years
  Tretaa ....  3,600 Divine-years x 360  =  1,296,000 Human-years
  Dwaapar ... 2,400 Divine-years x 360  =    864,000 Human-years
  Kali .......... 1,200 Divine-years x 360  =    432,000 Human-years
  Total   =   12,000 Divine-years x 360  =  4,320,000 Human-years

 *because        1 Human-year         = 1 Divine-day
                      360 Divine-days      = 1 Divine-year 
    therefore      360 Human-years    = 1 Divine-year
therefore  4,320,000 Human-years x 1,000 4-Yug period
                    = 4,320,000,000 years = Brahmaa's day and
                    = 4,320,000,000 years = Brahmaa's night

Thus  8,640,000,000 Human-years  =  Brahmaa's one day and night
Thus  8,640,000,000 x 360 days (Brahmaa's days) = Brahmaa's one year
And Brahmaa's age = 100 Divine-years 

So Brahmaa's age = 8,640,000,000 Human-years x 360 days (Brahmaa's day+nights) x 100 years

Beyond Tri-Lok, from Mahar Lok, to Tapah Lok, to Brahm Lok 1,000 Human 4-Yug period is one day and the same period of time, 1,000 Human 4-Yug, is one night in which Brahmaa Jee sleeps. When Brahmaa Jee night ends, then our Kalp starts on Prithvi, and it ends when Brahmaa Jee's day ends.

Kalp is the largest time period known on Earth.
Kalp = 1,000 Human 4-Yug period (4-Yug means Sat, Tretaa, Dwaapar, and Kali).

This is Brahmaa Jee's day only and He has His night also of the same length. In the day time He is awake and creates the Universe. In the night time He sleeps and it is the time of Pralaya. At that time it is all dark and water everywhere, no creation, no light except of Rishi's light, and everything is in sleep state. Brahmaa Jee with the help of Tamo Gun stops His Creation, stays calm and the whole Universe enters in His body.

When Brahmaa Jee's night ends, our Kalp starts on this Prithvi. In one Kalp there are 14 Manu - Lords of Manvantar. Because one Kalp is of 1,000 Human 4-Yug period, thus one Manu rules for 71 9/16 Human 4-Yug period.

71+9/16 Human 4-yug period  or 1 Kalp   = 1 Manvantar (present Manvantar is the 7th)
1,000 Human 4-Yug period  or 1 Kalp      = 14 Manu Period
1,000 Human 4-Yug period  or 1 kalp      = Brahmaa Day
1,000 Human 4-Yug period  or 1 Kalp      = Brahmaa Night
2,000 Human 4-Yug period  or 2 Kalp      = Brahmaa's one day+night
                       Brahmaa's 360 days       = 1 Brahmaa Year
                        100 Brahmaa Years       = Brahmaa Jee's age

So 1 Brahmaa Year     = 100 Brahmaa years x 360 Brahmaa Days x 2,000 Human 4-Yug
                               = 36,000 Brahmaa Days X 2,000 Human 4-Yug 
                               = 36,000 Brahmaa Days X 

50 Brahmaa Years      = 1 Paraardh (presently 2nd Paraardh is going on)  
                                     Brahmaa Jee's half age

And these 100 Brahmaa Years, which is Brahmaa Jee's age, also pass quickly.

Now these 100 Brahmaa Years is Bhagavaan's one Nimesh. This Nimesh, from Paramaanu to 100 Brahmaa Years is all powerful, but still does not control Shree Hari. It rules only Jeev with physical body.

Our Position in History
We are located in the fifty-first Brahmaa's year of the life of our Brahmaa.
Within that Brahmaa's year, we are in the first Brahma day, called the Varaah Kalp.
Within that Brahma day, we are in the seventh Manvantar, and in the 28th MahaaYug of that Manvantar. This would place us at about the 454th Mahaa-Yug of the 1,000 Mahaa-Yug that comprise this day of Brahmaa.
Within this Mahaa-Yug, we are in Kali Yug. The 5100th year of Kali Yug will correspond to the year 2,000 A.D. That means that we are fairly early in Kali Yug and this age will continue for more than 426,000 more years.

Some Other Views
Some other learned people have described it in another way:---
Shree Yukteshwar -
In the introduction to his book The Holy Science, Shree Yukteshwar describes an interesting variant of the Hindu theory of ages. According to him, "...the Sun, with its planets and their Moons, takes some star for its dual and revolves around it in about 24,000 years of our earth-a celestial phenomenon which causes the backward movement of the equinoctial points around the zodiac. The Sun also has another motion by which it revolves round a grand center called Vishnu-Naabhi, which is the seat of the creative power, Brahmaa, the universal magnetism. Brahmaa regulates Dharm, the mental virtue of the internal world."

Yukteshwar goes on to say that the Hindu almanacs, which correspond to the traditional PauraaniK model described previously, are in error. The error crept in during the dark years of Kali Yug when scholars misinterpreted the scriptures. Regarding the conventional view that we are currently in Kali Yug, Yukteswar says flatly that it is not true.

Yukteswar's model thus differs from the traditional in the following respects:
--A cycle of four Yug takes 24,000 years instead of 4,320,000.
--The Yug alternate between ascending and descending trends instead of always proceeding in the same order. This alternation becomes necessary once you posit that the ages result from our changing distance from Vishnu-Naabhi, rather than a deliberate divine intervention at the end of Kali Yug.
--The greater cycles like Kalp, Manvantar, and lifespan of Brahmaa go unmentioned.

Note:  Some people say that the numbers of Divine years are not the number of Divine years but are normal Human years so the whole Chatur-Yug period is not of 4,320,000 years but is only 12,000 years, but it does not seem logical, as Raam ruled in Tretaa Yug for 11,000 years. Besides many other kings described in Bhaagvat Puraan have ruled for thousands of years in Sat Yug, say 60,000 years etc. So this is not possible with the Chatur-Yug of only 12,000 years.

Alain Danielou -
Alain Danielou has written a number of books on the spiritual traditions of India. In the book "While the Gods Play", he quotes the Ling Puraan and derives numbers from it much different than those in the traditional interpretation described previously. In this version, the life span of the gods is 4,320,000 human years. This period is divided into 71.42 Manvantar. Each Manvantara is divided into the four Yug: Satya, Treta, Dwaapar, and Kali. As a result, the length of these Yug is as follows:

Satya (or Krit) Yug:   24,195 human years.
Tretaa Yug:               18,146 human years.
Dwaapar Yug:            12,097 human years.
Kali Yug:                 604,872 human years.   Totaling =  659,310 Human years

By Danielou's reckoning, Kali Yug began in 3012 B.C. and will end in 2442 A.D. By that point, the last traces of the present human race will have disappeared. We are supposed to be the seventh manifestation of the human race; the previous ones appeared in 419,964 B.C.; 359,477 B.C.; 298,990 B.C.; 238,503 B.C.; 178,016 B.C.; and 118,529 B.C. Our race appeared in 58,042 B.C., which according to Danielou corresponds to the advent of Cro-Magnon man. Danielou also suggests that Neanderthal man might be the race that precedes ours.

Danielou's version thus differs from the usual theory in the following ways:
--He takes 4,320,000 as the lifespan of the gods, rather than the length of a Mahaa-Yug.
--He divides the 4,320,000 period into 71.42 Manvantaras, rather than dividing a Kalp into 14 Manvantar. His Manvantaras are thus much shorter than in the usual version.
--He states that each Manvantar contains a single Mahaa-Yug, instead of the usual 71 Mahaa-Yug. His Mahaa-Yug are thus much shorter than in the usual version.

Danielou makes a couple of other comments worth mentioning. On the subject of why the scriptures portray a year as 360 days in length, he states - The number of days in a year is not constant. The rhythm of the earth's rotation varies over very long periods. A figure of 360 is considered to be the average. In referring to the cyclical nature of the ages, Danielou also makes the following very interesting statement: "The circle is an illusion, for the cosmic mechanism is in reality always formed of spirals. Nothing ever returns to its point of departure. However, the circle does give us a simplified image.

Unfortunately, he does not expand on this concept any further.

Cyclic Catastrophes
A number of periodic catastrophes are described in the Hindu scriptures:
--At the end of each Kali Yug, some type of destruction takes place. The most recent instance would be a bit under 4 million years ago. Other instances should be found every 4,320,000 years before that.
--At the end of each Manvantar, a great flood wipes out most life on earth. The most recent occurrence would be 120,534,000 years ago. Other instances would occur at intervals of 306,720,000 years.
--At the end of the Kalp, all life on earth is destroyed. The most recent instance would be 2,267,574,000 years ago.
--At the end of a life of Brahma, the entire universe and all its heavens and hells are destroyed. The current universe would have come into existence more than 150 billion years ago.