The phrase "It is what it is" means:

• Accepting a situation as it stands, without trying to change it.
• Acknowledging reality, even if it’s unpleasant or disappointing.
• Recognizing that some things are beyond your control.

In other words:

It’s a way of saying, “This situation cannot be changed, so you have to deal with it as it is.”

Example:

If someone loses a game and says, "Well, it is what it is," they mean they accept the loss and won’t dwell on it. Would you like examples of how to use this phrase in conversation?