Google - I am thinking of buying an electric guitar, but?

"Electric guitar" can mean almost anything. It can be an acoustic guitar with a microphone in the sound hole or it can be steel strings with an inductive pickup beneath the strings. If there is no sound hole, it makes almost no audible sound and the electronics produce all the sound. So you can use earphones to avoid bothering neighbors. Here is some technical information. You don't need to fully understand this stuff but you do need to be aware that it is there.
www.buildyourguitar.com/resources/lemme/