In the online life, security is always a concern. The following link will show the amount of time a PC needs to find your password. The password cracking programs use sort of random generators but are clever enough to check for complete words. So never use a word which exists in the dictionary. As usual, the following factors are important for a safe password: 1) combination of lower and upper case, 2) better to be 16 character long, 3) use numbers and special characters.
http://howsecureismypassword.net/
Examples:
cghftkd 32 sec (8 characters, only lower case)
cghf6tkd 3 hour (9 char, lower case and number)
cghf+6tkd 2days (10 char, lower case, number, and special character)
cGhf+6tkd_qrz 5 Million years (13 char, lower/uppaer, number, special char)
cGhf+6&Vtkd_qPrz 193 Billion years (16 char, upper/lower, number, special char)