Are hot wallets and exchange wallets same or there is any difference ?

All exchange wallets are hot wallets but all hot wallets are not exchange wallets. For example , Trust wallet is a hot wallet but not exchange wallet but binance exchange wallet is a hot exchange wallet and so are other exchange wallets.

Could you please give me some example of decentralized wallet?

I would love to answer - Metamask wallet.

Why do not you use hardware wallets despite being most secure?

Because hardware wallets have to be carried separately and need to connect with devices like laptop which seems cumbersome to me . Hardware wallets also seem difficult to use .

Thanks for being there .