Just updated from elements 18 to elements 2020. Should I now uninstall earlier version or leave both on computer? using windows 10.
I've moved your post to the Photoshop Elements forum where you are more likely to get answers relevant to your question.
The two programs are entirely separate and can safely coexist on your computer (if storage space is not a problem. The versions also have separate catalogs. When you installed 2020, it converted your 2018 catalog to a new one. Your old catalog has been renamed with a suffix of "1" attached. So, if you open 2018, you will have to browse to that renamed catalog.
You can consider the 2018 catalog as a kind of backup for your work that may be useful in the future.
BTW, Elements 2020 is actually version 18. Elements 2018 (which is what I assume you are referring to) is actually version 16. 🤓
Many thanks for help. I am still new at this.
Ok but if space is an issue can I delete 2018
"Ok but if space is an issue can I delete 2018"
Not delete, but uninstall.