question about Photoshop elements 2018

Photoshop Elements is sold as a perpetual license. You pay once and you can use it for as long as you have got the computer hardware and operating system to run it. That won't be for your entire life - just as long as you've got a supported computer and operating system.

Photoshop - the big brother of Photoshop Elements - is completely different software to Elements. It's aimed at professionals with lots more features but it takes longer to learn. Photoshop (Not Elements) is only sold on a subscription basis. You pay a monthly fee to use it.

Be aware that the current version of Elements is Photoshop Elements 2019.