Joule- the work done when you apply a force of one Newton over one meter. (Measurement of energy transferred, or as you may have heard it called, work.) Watt- quite literally, joules per second. So, the amount of energy transferred over time/ work done over time. (In x time you have done y work. Watts=x/y, y= joules, x= amount of time in seconds) Ampere- this is for current, which is the flow of electric charge Coulomb- is a unit of electric charge, which is a unit of the electrical current over time. You may have heard some say "amperes per second" or "amperes per hour", which is another way of saying what a coulomb is. (Think of amps as meters and coulombs as meters per second) Volt- this is a derived unit, which means it's not a base unit, and comes from other things, but basically, this measures the potential energy if electric current is flowing. Reading up on ohms law will be SUPER helpful to understand how all these relate. Like seriously, I wouldn't have passed this stuff in highschool if I didn't have ohms law down.