The particle भी means “also” or “too”.

Rāmu also went – रामू भी गया 

रामू  = Rāmu. भी = also. गया = went.

भी can also be used after a pronoun

I came too – मैं भी आया

मैं  = I. भी = too. आया = came.

Here are other pronouns that you can substitute with “I… too”

We also – हम भी

You as well – आप भी

He/She as well – वह भी

They too – वे भी

भी can be added with other words to form new words:

भी with indefinite pronoun कोई (any) will become “anyone”

Nobody – कोई भी नहीं

Anything – कुछ भी

The word जब (when) with भी will be जभी or “whenever”

The word तब (then) with भी will be तभी or “even then”

Whatever – जितना भी

Whoever /whichever – जो भी