An Exclusive-Rights Free Agent is an NFL player who is not under contract, but has only two years of NFL experience. If his former club makes him an offer at the three year veteran minimum salary, then that's it, he has to take it or leave the NFL. These guys have no right to negotiate with other teams. They are "free" only in the sense that they're free to quit.
Senio Kelemete was a 5th round pick by the Arizona Cardinals in 2012. He played 1 game for the Arizona Cardinals in 2012, and spent 2013 on the Saints practice squad. He was a reserve, backup for the guard and center positions for the Saints in 2014.
He can thus be signed at the minimum salary of $585,000 the league's set salary for his experience.
The Saints also have three players who can be resigned as RFAs.
A Restricted Free Agent is an NFL player who is not under contract, but has only three years of NFL experience. The Saints have until 4 PM ESTon March 10th to make an offer for their RFAs. The team would then have the chance to match any other offers made by other teams. A restricted free agent may then enter into negotiations with other teams and can sign an offer sheet. The Saints would then have until April 29th, to match any offers. Various rules apply to draft compensation for RFA, such as the level of contract offered by the home team as well as the round from which the player was drafted. UDFAs have no compensatory draft picks and a team only has right of refusal, and the right to match any offer.
The three RFAs are, Defensive lineman Tyrunn Walker, offensive lineman Bryce Harris and running back Travaris Cadet.
And now it's a done deal.