The 2019 NFL season does not officially begin until March 14.
That's what the NFL refers to as the start of the league year, and the significance of that date at 4 p.m. ET is that the 32 teams can start making major personnel moves to improve the product on the field.
Those moves include signing free agents in an effort to eliminate weak spots and improve areas of strength.
While teams can get significantly better by signing star players in free agency, the key to long-term success in the NFL remains the ability to find talented players in the draft and then coaching them up.