What Is Password Space?

Password Space definition and explanation.

Password space is the total amount of passwords that can be potentially created from a given alphabet, or set of characters for a given maximum password length. This is a measure of how many random guesses one needs to perform during a brute force attack to find any password within, and thus is a measure of security and vulnerability of passwords.

The size of the potential password space relies on the characters that are enabled (letters, numbers, symbols, etc.) and the length of the password. Thus, the more complex and the longer passwords are used, the larger the potential password space created is and the harder it is for adversaries to brute force an otherwise unguessable password.
For example, the English dictionary with 26 letters (a-z), would create a password space of 26^P where P is the length of the password. If we add case-sensitivity and numbers 0-9, this would change to 62^P. (a-z,A-Z,0-9). Note, that unless passwords are randomly generated, dictionary-based attacks and password guessing may simplify the attacks significantly, so password space alone is not a perfect measure of password security.