Touch move rule in chess

 I was playing chess with my nephew Aniruddha.

Accidentally I touched one of my pieces when playing.  Actually that piece was not the piece I wanted to move.

Aniruddha started pressurizing me to move the same piece which I accidentally touched !!!!!  

His pressure was upto such an extent that I hurriedly moved that piece without thinking.

Aniruddha instantly captured it and removed it from the board  !!!!

I asked him about this.

He said it is  Touch - move rule.

What is Touch - move rule  ???

If a player  touches a piece on the chess board , they must move that piece, if it is possible.

If the piece is in such a position, like it is blocked, player is not required to move it.

If the player touches  opponent's piece, they may be required to capture it if it is possible.

Eventually I lost this game....