A lucid dream is an extremely vivid dream. in a lucid dream you are aware that you are dreaming. you can train yourself to do reality checks throughout the day so it gets cemented into your subconscious. this way you will do reality checks in your dream to see if you are actually dreaming. this is a way to become lucid. common reality checks include holding your nose shut and looking at a digital clock. this is because in your dreams you can still breath if you hold your nose shut, and numbers are disordered commonly. once you are lucid you have the power to do whatever you want. fly, make things appear, make things disappear, or change locations...the list is endless.
Guy: heyyyy girl i had a fun type in your bed last night
Girl: EXCUSE ME!!
Guy: What! you liked it in my lucid dream!