Why use tags?

Why Use Tags?
The short answer: Tags help you find stuff.
Where did I file that document?
Typically, we file stuff alphabetically and group them in folders. That is a hierarchal filing system. Trouble is you have to remember what folder you filed it in.
For instance, should I file this article under blog posts, article, tags, or indexing? For example, In this example I can tag a document with as many key words as I want and a search will find all files related to that keyword. Of course, I can use multiple tags in my search. WA thinks tags are so important they won't let you file a blog post with out assignin at least three tags to the post.
Evernote
I've used Evernotes for going on 20 years. Evernotes is my backup brain. Evernotes says less than 2% of their users use tags. Evernote experts recommend minimizing Note Books and using tags as the primary way to find things.
My filing sytem
I have Notebooks for my major interests and my major projects. I use tags for what the file is about. I also have tags to indicate status of the file.
It works whether I am organizing my hard drive or organizing files in evernotes. Many programs do not provide for tags then I will add my tags at the end of an article like this:
#article #blogpost #tags #indexing
Then I use the operating systems global search and it will find all the #articles I am workin on,
Hugh
Categories are must but tags are not, I use both to make my user experience extremely delightful.
Wishing you well and a terrific day.