The Skill Tree in Destiny is similar to Talent or Upgrade Tree in other online games. Each subclass has an unique Skill Tree. By leveling up and using you skills, players can eventually unlock every ability and upgrade.
Although players can unlock everything, players may only have 1 upgrade in each upgrade column. Each upgrade column consist of 3 upgrades.
For the 3 columns consisting one's abilities, players can choose more than 1 upgrades.
