Any time Linux Lite goes to a new x.0 version it's a fresh install, & then a reinstall of anything that is not included with a base version of Linux Lite. Then that version can be automatically upgraded to versions x.2, .4, .6, .8. Just to mention to you, you don't have to upgrade to version 4.0 right away. If you are using 3.0 to 3.8, those versions are supported until April of 2021. So it's something for you to think about. You can do a fresh install & reinstall all your programs. Or you can stay with what you have for over 2 1/2 years. I suggest not to rush & think about what you'd like to do.