debug - the steps you take to fix errors in your code. Check out the story of Rear Admiral Grace Hopper, a pioneering computer scientist, and one version of where the term "debugging" came from.
loop - a piece of code that is continually repeated until certain conditions are met. The conditions contain an exit routine to tell the computer when to exit the loop. Loop statements typically start with the word(s): do, for, or while. If your loop code does not contain a valid exit routine, the computer will be caught in an infinite or endless loop, and you will have to debug it. However, there will be times you want to code an infinite loop.
syntax - the spelling and grammar of a programming language. Each programming language has its own syntax rules, and the computer expects the code you write to follow these rules exactly. Otherwise the code may not work as you want it to. Then you will have to debug it.
variable - a container to hold some piece of information that is usually used in more than one place in your code. The information can be a string of characters, a number value, or the result of some calculation or database call. A variable is typically declared at the top of a script or near where it will be used. The name of the variable is on the left, followed by an equal sign, followed by the item being assigned. For instance myvariable = "foo". Learn more about variables at Kids, Code, and Computer Science.