Trying to Understand Football 3: The terminology

So we are now 'all in' with this football malarkey. Football boots - check. Properly sanctioned shin pads - check. Team football kit & practice ball - big expensive cheque.
He may not be able to keep hold of the ball worth a damn but, by crikey he looks the part out there.

One of the drawbacks to never having watched any football is that I have a woefully inadequate grasp of the rules and culture of the game.
This means that my offspring and I are often left in a state of bemused incomprehension at football training as the coach raps out orders like 'Mark up and stay around the box', or 'receive it on the back foot and then finish'.

What in seven hells are these people talking about? Words appear to completely change or reverse their English meaning when exposed to football.
'He conceded the goal' does not mean that he stood aside and let it roll in (although this would be a rather apt description of my son's performance in goal to date). Apparently it just means that a goal has been scored?

Perhaps commenters can assist me with the following bewildering sayings or add some of your own.

- playing through the ball
- a good engine on him
-Finishing
-down the line
-back foot
- first touch
- close control

One thing I am very happy about is that the practice of 'Shirts and Skins' appears to have been dropped in the twenty first century. I hope that most of you are too young to recall this method of identifying teams that was prevalent amongst PE teachers when I was in secondary school.
Basically, one (lucky) team would be allowed to compete fully clothed, whilst the other players would be forced to strip off their shirts and play 'nipples out'.
Generally speaking; sadistic PE teachers would always place the fattest children on the 'Skins' team so that they could be berated and cajoled into shame by their fitter classmates. I can vividly recall one unfortunate boy in tears following this practice as the whole class chanted at him to 'get his glands out for the lads'.  Poor chap. I hope that he recovered & is living happily somewhere.