Here is some more info on the types of free agents and compensation (from the NHL):
FREE AGENTS SUBJECT TO COMPENSATION AND RIGHT TO MATCH - GROUP 2
The players listed below have been tendered a qualifying offer by their respective Clubs and are subject to draft-choice compensation and right to match. The draft choice compensation scale is based on compensation offered by the new Club:
OFFER COMPENSATION
$1,339,575 or below None
Over $1,339,575 to $2,029,659 Third-round choice
Over $2,029,659 to $4,059,322 Second-round choice
Over $4,059,322 to $6,088,980 First-round and third-round choice
Over $6,088,980 to $8,118,641 First-round, second-round and third-round choice
Over $8,118,641 to $10,148,302 Two first-round choices, one second- and one third-round choice
Over $10,148,302 Four first-round choices
UNRESTRICTED FREE AGENTS - GROUP 3
The following players have qualified for Group 3 Free Agency (age 27 or older or with at least seven Accrued Seasons) and are Unrestricted Free Agents.
UNRESTRICTED FREE AGENTS - GROUP 6
The following players qualify for unrestricted free agency, having met the requirements for Group 6 free agency. This group is defined as players whose contracts have expired, are age 25 or older, have completed three or more professional seasons, and (i) in the case of a player other than a goaltender, have played fewer than 80 NHL games (regular-season and playoff), or (ii) in the case of a goaltender, have played fewer than 28 NHL games (regular-season and playoff). Please note that these amounts are subject to pro-rating due to the 48-game season in 2012-13.