Tags best practices

For your readers sake you might consider tagging old posts. Not mandatory though.

There’s a long story about tagging and categories. One difference is that Categories have hierarchy, Tags do not.

Please consider reading through some of the discussions on the wp-hackers email list:
https://comox.textdrive.com/pipermail/wp-hackers/2006-September/008189.html
https://comox.textdrive.com/pipermail/wp-hackers/2007-April/011894.html

Also this might shed some light:
https://lorelle.wordpress.com/2005/09/09/categories-versus-tags-whats-the-difference-and-which-one/

Many thanks for the links MichaelH, these articles have made me pretty clear on the differences.

Thank you