What is bulnder and how do I avoid one

Sort:
elgatogang

I am new to chess and sometimes when I play against Jimmy or Martin (computers for beginners) I would always have made a blunder so how do I avoid one 

Tee

https://www.chess.com/terms/chess-blunder

this may help

tygxc

A blunder is a move that turns a won position into a lost position.
To avoid blunders always check carefully that your intended move is no blunder before you play it, no matter how obvious the move appears.