A pop up blocker is a program which prevents a new browser window (known as a pop up) from opening when you click on a link or a button. They are often used to protect you from viewing ads which load in pop up windows.

Sometimes, however, you may want to disable pop up blockers. In RCU Online Banking, for example, some applications may open in pop up windows. When you are using RCU Online Banking, you will want to enable pop up windows so you can connect to them.