Wikipedia defines a glitch as a short lived fault in a system.  It also lists three types of glitches, a computer glitch is  an error in software or hardware that interrupts how a computer program runs, an electronic  glitch usually is an error in design that interferes with the electrical flow. Finally, a video game is a flaw in programming that keeps the game from running correctly.  Without understanding the terms, a glitch could be mislabeled.  

An example of a computer glitch is when votes made on electronic voting machines are changed as the voter is watching.  Electronic glitch example is when a throttle position fault is detected because throttles are pushed into the stops with more than 30 pounds of force.  This problem was originally thought to be a mechanical failure.  And the one that we are all familiar with but sometimes don’t recognize is the video game glitch.  Super Mario Bros is full of these glitches.  An example of one is when the player dies on the cloud level (by being hit by a stray hammer), the player starts off the next life at the top of the screen, on top of the word "MARIO", unable to move!

Glitches occur all the time and can cause a serious disruption of everyday life if one is not prepared for them.  Most of the time they are not recognized as occurring, but when they are, a resolution is usually found and the item disturbed by the glitch goes back to working normally therefore, making life a little easier.