Explain what does it mean to have a government shutdown

A government shutdown is when non-essential discretionary federal programs close. The president must do this when Congress fails to appropriate funds. In the normal budget process, Congress appropriates funds by September 30 for the following fiscal year. When that doesn't happen, then Congress enacts a continuing funding resolution. If Congress can't agree on one, it forces a shutdown. It signals a complete breakdown in the budget process.

Is there a passage that comes with this question or should i know this right off the bat, because if it is, i probably have short term memory loss or college is too stressful