For example, the Azure Whelpling belongs to the Dragonkin family. However, it has Beast, Magic, and Elemental abilities in addition to a Dragonkin attack. Different attacks are strong and weak against different family types. Having a diverse spell selection might increase your chances of being prepared with a strong attack against an opposing team.
The World of Warcraft is going back to its roots with WoW Classic. Giving players the chance to return to the game as it was around the time of its launch, WoW Classic is set to launch worldwide on August 27. However, ahead of its imminent release, the team at Blizzard are offering a closed beta test for WoW Classic, and we've got all the details players need to jump in on the action.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.