A fundamental thing in Luau you must understand is that there many different types of Values including:

1. nil = the absence of a value or nothing

2. boolean = can be either true or false

3. number = just a number

4. string = sequence of one or more characters enclosed by a single or double quote

Don't worry too much about these next ones, they will be covered later in the scripting course

5. table = stores key-value pairs like a dictionary or array or object in other languages

6. function = executable block of code 

7. thread = a coroutine

8. userdata = instances like part, model or player

Understanding Booleans and Nil

Something crucial you must understand in Luau is truthy and falsy:

if a value exists, the mere fact that it exists makes it true or truthy, if a value doesn't exist it is nil which is falsy and if it is explicitly set to false then it is also falsy 

There are only 2 falsy values which are nil and false , everything else is truthy including: true, 1 , "hello" , 0 , 37 , the presence of a table , etc etc