What actually defines a strong password for online account and activities?

[Min George]

There has been emphasizes on using strong passwords for online activities. And that can be confusing. Are strong passwords all about the length of the password or the mix of characters for the password?

 

[Fidelia]

A strong password should be 15 characters long. It should be a mix of upper case, lower case, numbers and symbols.

 

[neku]

The definition of a strong password varies, some want a 8 character password, others want 10 characters, and still others want 15 characters or more, the combination of characters also varies.