Tenders pertain to qualifying offers that NFL teams might give to restricted free agents who had played for that team.
A restricted free agent is a player who has accrued three seasons and whose contract expired. They can talk to and sign with any team, but their previous team might want something in return.
For example, a first-round tender in 2022 included a one-year contract worth $5.6 million or 110% of the player's base salary the previous year, whichever is more money. If the player's previous team doesn't match an offer sheet from another team, that previous team can receive a first-round NFL Draft pick from that new team.
There are other tenders like a right-of-first-refusal tender, an original-round tender and a second-round tender.