Scope is the accessibility of variables. It is based on the variables available in a file(s). There are two types of scope, global and local.
A variable that is declared outside of a function body and that can be accessed and modified across files has global scope. Local scope
refers to a variable that is only accessible within a function. Global variables are to be avoided because it can create buggy code. It
could cause unintentional side effects and change/ alter the physical outcome of your code. Javascript has a command called ‘strict mode’
to account for any variables that are declared without the var keyword. It helps to avoid code that is hard to debug. A side effect is the
result of a function that reaches outside of its local scope by accessing a global variable. This may cause an intended change, but may
also cause an unintended change, which may return a different value than intended. On the other hand, a pure function is a function free
of side effects and will always return the same value. To hoist means to raise up. In the context of JavaScript, hoisting is the behavior
in which variables and function declarations are processed before any code is executed. Basically, no matter where a variable is declared,
it will equate to declaring it at the top of its scope.