Most of the rhythms we have looked at have all been on the beat. They will usually hit on the 1, 2, 3, or 4. This feels steady and at it's strongest, but what would it sound like if we were to change the main beats to be on the "1 and", or the "2 and" etc. This is where the word Syncopation turns up and says "hey, that's me!". When we count beats, we can count the sub-beats with phrases such as "1 e and a, 2 e and a..." which you can revise here. If we place a note on the 'e' 'and' or 'a' we create Syncopatoion and this makes things sound a little more interesting, as the notes aren't where or brain expects them to be. This can make some things more memorable as we don't expect to hear them where they are.
If we take a melody:
it sounds okay, nothing too fancy and it does the trick, but what if we move some of the notes over a quaver (8th note)? We can create something that has a little more movement to it and sounds a lot more interesting as you can hear below:
All we have done is played some of the notes a little earlier or a little later than the original, and it creates this realistic sound rather than a robotic sound.