You use passwords to log into a whole range of online sites and services including email accounts, online banking, social media, and gaming sites. If you use the same password for everything you are more susceptible to a cyber-attack or identity theft.
Secure passwords should contain both upper and lower case letter, numbers and symbols. The actual mix of your password will depend on the requirements of the site or service you are going to use it for.
To get secure passwords that are significantly harder to guess we recommend using a site such as https://identitysafe.norton.com/password-generator.
Once you have generated your secure password there is no point using that same password for everything you use online. If you do you create the weakness that if that password is comprised on one site then a cyber-criminal potentially has access to all your online presence.