(strâng pas´wërd) (n.) A password that is difficult to detect by both humans and computer programs, effectively protecting data from unauthorized access. A strong password consists of at least six characters (and the more characters, the stronger the password) that are a combination of letters, numbers and symbols (@, #, $, %, etc.) if allowed. Passwords are typically case-sensitive, so a strong password contains letters in both uppercase and lowercase. Strong passwords also do not contain words that can be found in a dictionary or parts of the user’s own name.
How To Create Stronger Passwords This page from Microsoft advises one on how to create passwords that will be less likely to be cracked.