Also just a quick note, the rotation actually just refers to the 5 starting pitchers. Starters and rotation is used interchangeably. Starters only pitch once every 5 days. Rarely do they ever pitch all 9 innings but they handle the majority of the game (unless they're getting killed then they get pulled early). Pitch counts are very important here. If a starter has thrown 100 pitches in 1 game, they will likely be pulled soon.
The rest of the pitchers make up the bullpen (relievers). They come in and pitch after the starters. Theres no 5 day period for these guys. They are mostly available for every game. But that also limits them to pitch much less per game. Most relievers only go a maximum of 1 inning. A lot of left handed relievers tend to go even less than 1 inning as they are considered specialists put in to get left handed batters out and then leave. Fry may end up as one of these specialists, although he just joined the team from the minor leagues so it's hard to say what his role will be (and with how bad the Sox bullpen is they probably dont have a luxury of using specialists).
The bullpen guy who pitches last when the team is winning is called the closer. Typically it's the best reliever you have. That's Jones, the guy who they put in today. He just blew it. On that note it cannot be understated how bad the White Sox bullpen is.
I dont know how much of this you knew or didnt know and there are exceptions to everything I said here, but hopefully that info helps.
I also want to reiterate what they said about the minor league system above. It's VERY unique to the sport of baseball and very popular to follow in it's own right. To give you an idea, the Sox have a minor league player thats already been paid out 30 million dollars to (more than most all of the White Sox major league roster has made) and yet the highest league hes played in is the ~7th highest league there is. Seems insane on the surface but it shows what a good minor league system can do for you down the line.