They coach the same game, with the same-sized fields and same oblong ball. They both wear whistles, headsets and sunglasses that hide sleep-starved eyes closer to Xs than O's.
But the difference between being a head football coach in college and the NFL is like the difference between Wal-Mart and Wall Street.
"When you're in the NFL, and you're going to do something that's going to help you win, no one ever says, 'What does it cost?'" said Jerry Glanville, who coached at Portland State more than a decade after coaching the Houston Oilers and Atlanta Falcons.
"When you're in college and you say, 'I want to get this done,' they say, 'We don't have the funding. By the way, would you go raise the funding?'"
The differences go well beyond that, including the challenge of recruiting high school athletes, how the players interact with each other and the day-to-day responsibilities of the coaches.
"When kids get in trouble and screw up in college, everybody feels the responsibility for it," said Seattle Seahawks Coach Pete Carroll, USC's coach from 2001-09. "Here, it's more on the player. You don't feel so terrible because the players are grownups. They're getting paid, they're professional. They're supposed to take care of their own world.
"In college, they make everybody feel responsible for it. The [athletic director], the president, the head coach, everybody feels responsible."
Carroll is among seven current NFL coaches who have been college head coaches, the others being Philadelphia's Chip Kelly, Buffalo's Doug Marrone, Tampa Bay's Greg Schiano, San Francisco's Jim Harbaugh, Arizona's Bruce Arians and the New York Giants' Tom Coughlin.
While those coaches are gearing up for the final push in the NFL's regular season, their old college counterparts are hitting the road for that vital recruiting stretch between the end of the season and bowl games.
"What you have to have in a college coach is somebody who can absolutely bust his butt recruiting," said agent Bob LaMonte, who represents multiple NFL and college coaches. "I don't mean a little bit of the time. I mean 24/7, 365. The coach will sell his soul to the devil for time. He will not make it if he doesn't give his life over to recruiting.
"There's no end to the time you'll spend. If you don't do that, I guarantee you will fail as a head coach in college."
The recruiting that goes on in the pros is the courting of free agents, although those player decisions often hinge on which team is willing to pay more. There are exceptions, of course, but for the most part the ability to recruit is far more important in college.
"I took great pride in my recruiting," said Barry Switzer, the longtime Oklahoma coach who later won a Super Bowl as coach of the Dallas Cowboys. "I worked hard at it. First of all, I had a great product to sell. When you have the University of Oklahoma to sell, I'm selling Mercedes. I'm not selling Volkswagens. So I had an advantage. Kids were going to listen to me. Families were going to listen to me. We were winning tremendously in my era."
NFL teams play eight regular-season games on the road. In a sense, when it comes to recruiting, college coaching is one continuous road trip.
"My schedule [at Oregon], the day the season was over was a lot worse than my schedule here" in Philadelphia, Kelly said. "Because, you know, you're planes, trains and automobiles recruiting from Sunday night until Friday afternoon and hustling back and practicing, getting a practice in Friday afternoon, practice Saturday, practice Sunday, get back on a plane and fly around the country chasing down recruits.
"Maybe a misconception is when you're a college coach and the last game is done and then the bowl game comes, you don't have a month off. I would argue my schedule was more hectic from a recruiting standpoint than it was here. So I'm looking forward to being in the office every day and watching tape. That is the fun part of our job."
UCLA Coach Jim Mora, who formerly coached the Atlanta Falcons and the Seahawks, said he prefers college football because of the "energy and enthusiasm" surrounding the game, as well as the enhanced responsibilities coaches have.
"The relationships with players, it's different," he said. "They are younger. They are more impressionable. They need you more in their lives. You're dealing with mothers and fathers rather than wives and agents. It's much bigger than football.
"In the NFL, you are judged on one thing: Did you win or did you lose? In college football, you're judged on did you win or did you lose, but you're also judged on, are your students doing well academically? Are you helping them become responsible citizens? Are you introducing them to things in terms of community services, and things outside the realm of football? They don't do that in the NFL."
So much of the job comes down to selling the school on a prospect and his family. When Glanville was a linebackers coach at Georgia Tech in the early 1970s, it wasn't uncommon for him to be sharing a couch with a rival coach, sometimes a coaching legend, fervently vying for a recruit.