What assets to declare at balancesheet?

I am a freelance web designer. While calculating income tax my CA prepares P&L account, balancesheet. At the balancesheet I need to declare my assets. My questions are -

1.) What is an asset?

2.) If I bought anything non-related to my profession (like TV or AC) is an asset?

3.) Why should I declare asstes? Is it mandatory?

4.) Which is asset - I bought a computer mouse (and many other small things) and a trademill this year.

5.) Should I declare those things only which I have bills?

Pls help me.

Many thanks

Sourav