---You have the "call 7" = the 7 becomes a game winning ball for you only if you make in on a legal shot and call it and the pocket (hence why it is called the "call 7"). If you slop it in somewhere on a legal shot that was not called it is treated like any other ball that was slopped in and you get to continue your turn but it doesn't win you the game.
---You have the "wild 7" = if you make the 7 on a legal shot, even if it is unintentional or it goes into a pocket other than what was intended, then you win the game. That includes on the break. It is also very common for the wild 7 to not be allowed to be wild on the break but will be wild for the rest of the game, but if this is not specified before the match then wild means wild on the break too. When the 7 is agreed not to be wild on the break, it stays down when made on the break but it is also fairly common to play where any wild balls made on the break will spot back up immediately after the break (but it must be specified that you are playing that way otherwise the default is that they stay down). If you are getting the wild 7 and racking for yourself it is prudent to rack it where it has the greatest chances for going on the break, such as on the corner ball location, and if you are giving the wild 7 to someone else and racking for each other, it is prudent to rack the 7 in a location where it is not likely to go on the beak for them such as in the second row right behind the head ball. It is also very commonly negotiated before the match where the wild balls can and cannot be placed in the rack.
---You have "the 7" = wild 7. If call or wild wasn't specified, they mean wild.
---You have the "7 out" = "out" in this case means "on up", and since called or wild wasn't specified it means wild, so 7 out means (in 9 ball) that you have the 7 and 8 wild in addition to the 9 which is obviously always wild for everybody (unless you are playing a call shot variation of 9 ball).
---You have "the last two" = say the game is 9 ball, you win when you legally pocked the last remaining ball on the table other than the 9 ball on a called shot (others may play where the second to the last ball acts like a wild ball rather than a called ball but I don't think this would be common but in any case make sure you clarify all these type things before you start). Typically in 9 ball the last two balls left on the table will be the 8 and 9, but often enough because of what was made on the break or made earlier in the game, the last two balls might be the 7 and 9 or even the 5 and 9, who knows. Because of this, in 9 ball, "the last two" is very slightly more weight than the "call 8".
***When giving or getting weight, it is smart to spell out every last detail of all the above type things and never leave them to the assumption that your opponent has the same understanding of what certain terms mean that you, do or that they play these things the same way that you or everybody else you know does, because as sure as you don't explicitly specify every last detail your opponent is going to say things like "well xyz is the default for that around here/where I come from" or "that isn't how most people play it when you say that" or "I've never played it that way and didn't know that's what you meant" etc, whether they actually believe that to be true or not, and once you find yourself at that point it is at best a very messy situation and at worst a dangerous one.