As the season winds down, hundreds of college football players will soon be traveling to bowl games in various parts of the country. And hundreds of others will be off to a different destination: the transfer portal.

Created by the NCAA in 2018, the transfer portal has quickly become a key pillar of college sports – a resource for athletes, a program-building tool for coaches and a never-ending source of intrigue for fans. But some of the mechanics of the portal remain misunderstood.

With this year's college transfer market beginning to heat up, here's a look at how the portal works, how it's evolved in recent years and how it can benefit both athletes and coaches alike.

What is the transfer portal?

A 2019 article on the NCAA's website describes the transfer portal as a "compliance tool to systematically manage the transfer process from start to finish."

Put more simply: It's a database.

The NCAA made this database in an attempt to simplify the first step in the transfer process. In the pre-portal days, athletes would have to ask their coach for permission to contact other schools, then find ways to get the word out that they were available. Coaches, meanwhile, would have to use their connections and word-of-mouth referrals to identify transferring athletes. Now, it's all just there in one spot.

How does the transfer portal work?

The portal is not a shortcut for the rest of the recruiting process. Coaches still have to recruit. Athletes still have to ensure they're eligible to compete at a new school. The portal is simply a way to help the two sides connect more easily, and earlier.

What does entering the transfer portal mean?

Because the transfer portal is really just an online database, entering it just means that an athlete's name is uploaded to the database.

When an athlete decides they want to explore transferring to another school, they have to notify their current school's compliance office. And the compliance office then has two business days to put that athlete's name in the portal.

How has the transfer portal changed college sports?

It's important to understand that the NCAA transfer portal is merely a tool used by coaches and players to find new schools. What really changed the landscape of college sports, and allowed a sort of free agency frenzy, was the NCAA's rule change on immediate eligibility.

It used to be that if athletes wanted to transfer, they had to sit out a year before suiting up for their new school. But in spring 2021, the NCAA voted to allow athletes to transfer once and become immediately eligible. (Athletes are allowed to transfer a second time without penalty if they've completed their undergraduate degrees and are enrolling in a graduate program.) Since that rule change, hundreds of athletes have entered the portal each offseason, though not all find what they're looking for in their decision to switch schools.

Is the transfer portal the same for every sport?

While football and basketball might get the most media talk (and fan interest), yes, the transfer portal database includes athletes for all sports.

When does the transfer portal open?

In the Football Bowl Subdivision, a 30-day window to enter the transfer portal runs from Dec. 4-Jan. 2. There is also a spring window from April 15-30.

It's worth noting that these windows restrict when an athlete's name can be entered into the portal, not when they actually transfer to a different school.

Can players choose to stay at their school if they enter the transfer portal?

Absolutely, though it's somewhat rare in high-level college football. According to NCAA data, only 5% of FBS athletes who entered the transfer portal in 2020 or 2021 later withdrew and are assumed to be back at their original school.

This article originally appeared on USA TODAY: How NCAA transfer portal works in college football? What to know