When people look for computers (or phones, or internet access) they may know what they want it for now, but not what they want it for in the future. Of course you could buy something now and buy something else when you need it, but it could be more expensive that way.
It used to be some people would say they only use their computer for word processing and maybe a game like solitaire.
Then it became, use it for email, and web browsing. -internet access
Then add a digital still camera, you want to store and view photos with your computer. -larger hard drive, maybe a better monitor
Then add downloaded or streaming digital music and video. – high speed internet access, large hard drive for downloaded content, good video card, good sound system
I personally started off using computers for games, word processing and drawing (and printing).
These days I use them for my digital photos and video from my cameras. Keeping track of bank accounts, keeping accounting books, and taxes. Download music from iTunes and Amazon. Watching video by others-streaming, downloaded, DVD, or TV tuner. I use Word processing more for email and web sites rather than printing. I don’t play much for games on my computer anymore, but use my friends Nintendo Wii once in a while. I’m trying to print less and less and have been converting paper, film, and tapes to digital form stored on hard drive and/or DVD. I didn’t think I’d join social networking web sites or send text messages on the phone, that changed.
My parents as recently as a couple of years ago weren’t planning on watching video on a computer, now they do.
If you see a feature or something new, you may not use it now, but that will likely change.