Are you new to programming? Those terms are commonly used in every programming language.
Do a web search such as "computer programming definitions keyword" and you'll find explanations and examples.
In the following example, "var" and "int" are keywords. "=" and "+" are operators, "int" is a type, "17" and "99" are literals, "x" and "y" are variables and "print" is a built-in function.
var x: int = 17
var y: int
y = x + 99
print(y)