cutting copper pipe

Hi, Probably a numpty question, but can anybody tell me what sort of connection or coupling is pictured below please. Background is, I've had to replace a leaking handbasin mixer tap in my downstairs WC. The new tap comes with a fixing kit and flexi tails. I'm planning on using a pipe...

I'm new the forum, so I'll start off with a hi to everyone :) Great to a have a community of DIY'ers helping each other out. I'm also new to plumbing work. I thought I'd get some kit and a 15mm copper pipe and start practising. One thing I've noticed when cutting the pipe (with a pipe slice...