Difference between various kinds of buy/sell orders and their respective relation with trigger price?

General
1

difference between buy/sell order types of

  1. market

  2. limit

  3. SL

  4. SL-M

what exactly is there relation with trigger price ?

2

market order is when when you intend to buy at market available prices instead of a very specific price

 ‘Limit’ order is when you are very particular about the price you want pay for a stock.

stop loss order protects you from an adverse movement in the market after initiating a position. 

SL-M is the stoploss order which got executed at market price

You can read in detail  http://zerodha.com/varsity/chapter/the-trading-terminal/