Assuming the player accepts the offer sheet, the team has two options. They have 7 days to make their choice.
The first option is to exercise their "Right of First Refusal". This means that they match the salary, term, signing bonus and reporting bonus of the offer sheet, and the player is considered signed. Additional terms such as no trade/no move clauses or performance bonuses are NOT included, but they can be negotiated separately. If a team exercises this right, they cannot trade the player for one year (to the day).
The second option is to let the player walk, and collect their compensation from the team that submitted the offer sheet.