An op may refer to any of the following:
1. Short for operator, op is also known as chanop, which is short for channel operator; or ircop, which is short for IRC operator. An operator is a superuser in an IRC (Internet Relay Chat) channel that controls and moderates a channel. For example, if a user enters the IRC channel and harasses other users, the op can kick that user from the channel. There are commonly two types of OP's in each IRC channel an SOP (super operator) and HOP (half operator).
This term should not be confused with a computer programming operator, see the operator definition for further information about this term.
2. Abbreviation for an opinion that is used in chat and other text-based communications.
3. On a forum, op is short for original poster, the person who first started a topic.
4. With a telephone, an operator is a human or automated system that helps direct calls and assist with phone problems.
5. Op is also short for operation, when referring to a calculation performed by a CPU (central processing unit). For instance a "no-op" is a special CPU operation that does nothing, and a "flop" is a floating-point mathematical operation.
6. In video games, OP is short for overpowered, meaning a player, character, or item is very powerful or too powerful. In a game like Diablo 4, OP is a game mechanic short for "overpower" that describes the type of damage hit. For example, in Diablo 4 a normal hit is white text, a critical hit is yellow, an overpower hit is blue, and a critical overpower hit is orange. In Diablo 4, the formula for an overpower hit is the sum of your life + fortify * the OP multiplier.