Trading account is opened with a SEBI approved broker to enable a person to trade either from home through online or through the broker.It is only for buying n selling.Demat account is created with banks or other depositary participants for keeping purchased shares n issuing shares to the buyer,when one sells.

Demat account - type of account in which shares are kept either with NSDL or CDSL trading account - type of account with broking firm on which shares are traded for a person