string-operations

string is a sequence of characters (letters, symbols, spaces, tc.) that are written within a quotes such as: "Hello" or 'world'
concatenation: combines multiple strings using +
repetition: repeats strings using *
slicing: extracts part of string using [start::end]
string methods are built in function that can change or return info, which includes:
• .upper() = convers to upper case
• .lower() = converts to lower case
• .strip() = removes extra space at the beginning or end
• .replace(old, new) = replaces part of the string
• .len() = gets length of the string