Think of a piece of paper.
If it is flat on the table then the distance between two points is easily measured.
If you fold the paper several times then the distance between the same two points is considerably less.
Clear as mud.
'65
A measurement alters/collapses the quantum superposition of states. The key to understanding quantum mechanics is to acknowledge that any quantum system can exist is some non-physical non-intuitive configuration until a measurement/experiment is done on the system and the quantum system then alters/collapses into a state that we can physically observe.
Quantum entanglement is an extension of of this. You can have two particles created at the same point in space from some interaction which will be in some quantum entangled configuration (ie. opposing spins). They then shoot off in opposite directions until they are so far apart they are no longer causally linked (ie. it'll take light a 'while' to travel from one particle to the other). At this stage they are still quantum entangled. It is only when we do a measurement on one of the particles (eg: measuring its spin) that the quantum state alters into a particular state we can observe. Even then the observer will only know that that one particle he/she is measursing will have a preferred spin direction. You would need another observer measuring the spin of the other particle after entangled state collapses to tell you what the resulting spin is of this other particle. That info will take at best as long as the speed of light takes to travel between the two observers one to find out the particles have opposing spin. To say the collapse of the quantum entangled state travels faster than light doesn't make sense as no physical information is transferred at faster than the speed of light. It's against the laws of physics anyway for something physical to travel faster than the speed of light otherwise you'd be going backwards in time and you'll have cause and effect issues (ie. you'd could know the result of the measurement before the measurement is actually done).
I don't know if any of this made sense but if you're thinking to yourself this is just weird then you're right - it is weird. As the late American physicist Richard Feynmann said once "if someone says to you they totally understand quantum mechanics/physics then clearly they don't".