Xbox 360 help please!

[tobomoto]

Ok here goes... I got an elite 250gb model with 1 controller, leads and a wireless network thing (will be getting rid of soon) for a bargain price of £60. Got round the blokes house and ge said the dusc draw didnt open so i could have it for £20. Ok i thought cant be mych of a problem. It didnt have any games so i went round the local cash exchange thing and got assassins creed 3. Got home, set it up and i can play some games that are already on the hard drive (hitman, assassins creed 2, fifa 14 and some others).
Is the console jtagged or are they what the bloke has downloaded? sorry fir the long read but i dont know too much about this. Cool story bro ect ect.