You need to put together related topics this is how to rename category in WordPress. It was named something else when you started as the content increases in the amount it doesn’t fit anymore.
There are multiple reasons and it will be different for everyone else a few things I can tell would be the contents became broader as the posts or article increase.
You need a name which covers a larger topic or breaks it down to a smaller concentrated topic by distribution the content
FIRST, Login or sign in and click on posts to go to your contents
SECOND, It will expand with multiple options and choose and click on categories
THIRD, Hover your cursor around the one you want to rename and when you have multiple options shown. Click on the quick edit
LASTLY, You just need to change the name section or box and click on the update category button which is on the bottom right side