How to fix partially encrypted/mixed content errors after switching from HTTP to HTTPs (SSL)?

How to fix partially encrypted/mixed content errors after switching from HTTP to HTTPs (SSL)? HTTP (or Hyper Text Transfer Protocol) is the protocol or method used by which data is moved around the Web but HTTP is not secure. HTTPS (or Hyper Text Transfer Protocol Secure) is the answer to the data protection issue. It used to be mostly used by eCommerce and banking related sites. HTTPS