Why is it important that know the difference between NRML, MIS, CNC?

Information about various order types.

It is very important to know the difference between NRML, MIS, and CNC as you might end up placing a new order while squaring off your position which will cause you a loss.

Ex. Client X has 100 stocks of SBIN which he has bought using CNC. He wants to sell them today. He placed a selling order for them at market price but he didn’t know the difference between CNC and MIS. He placed an MIS order which opened a new position in the market because of which, The client has 2 open positions in the market (Unknowingly) which can be a potential disaster for the client.