Solo adventuring

Solo adventuring, or simply soloing, refers to the way of a player to achieve questing or other in-game tasks alone, without implying oneself into a party. It World of Warcraft, soloing is a mandatory process at early levels (usually below 10), designed to accustom the player to WoW gaming experience. Quests above that level are somewhat suggestive of grouping (which is especially true for those marked as "Group" or "Elite", or many quests above level 45-50), however are also designed so that solo players could also achieve them.

In fact, the only WoW content that discourages solo adventuring is instanced dungeons. As a result, the feat of soloing difficult instances is often an exiting and interesting challenge, often considered the proof that a player is good at playing the game (if the player succeeds).

Pros & cons of soloing
There are several pros and cons of soloing. Here are a few of them.

Pros:
 * No need to share exp, cash or loot
 * No wasting time on answering other players withing a group, especially when fighting
 * No waiting for other players
 * Better flexibility between changing zones or continents
 * No other players to ruin anything, like triggering traps or wasting opportunities

Cons:
 * Hard to do certain quests without a group
 * Longer time required for kill quests, especially when facing Elite mobs
 * May be dangerous to roam alone in hostile territories (even if you're max level)
 * Some encounters are specifically made to be fought by several players at once, being impossible to solo
 * Inaccessible instances - without a raid the best thing you can do there is get killed

Usually, it's up to the player to decide whether they want to go solo or group, but as with everything, a little of each is required for the better gaming experience.

Overgearing in solo
Occasionally, players at much higher levels or are overgeared may solo such content for achievements points (common for Death Knights and Paladins) bragging rights, or unique gear as a "trophy" or roleplay wear. At exactly what level group content becomes soloable can be difficult to determine, depending on player class, behavior of mobs, and associated gimmicks a player may or may not be able to outgear.