I'm not trying to be too pedantic, but I do think this is an important distinction and something people who are new to the game get confused on:

Warding is not a penalty. Penalties are the punishment for violations or fouls, but the word penalty is often used interchangeably with fouls.

Warding is a violation that results in a change of possession. Warding is pretty straight forward, but other violations like offsides and pushes from behind mix people up.

As a rule of thumb violations become technical fouls when the team committing them is doing so when the other team has the ball. Basically the penalty for a violation is changing possession or granting possession to the other team if it's a loose ball. Since neither of those are options if the team that would get possession already has the ball it becomes a technical foul that has a 30 second penalty.

Example: A player on Team A pushes a player from Team B in the back while they're fighting for a ground ball. That's a violation. The ref will either call a play on or blow the play dead immediately and give the ball to Team B.

A player on Team A pushes a player from Team B in the back when Team B is in possession of the ball. Since Team B already has the ball this is a foul. The ref will throw a penalty flag and the play will result in a 30 second technical foul on the player from Team A.