'Durability' means a lot of different things, as it's concept of how well things last over time.
'Strength' actually has a specific meaning in material science, as it's the amount of force per area something can take without causing significant plastic deformation. (ie, it doesn't bounce back when the load's removed)
'Toughness' is the amount of energy required before fracture, and because aluminium deforms to absorb energy, it's considered tougher than steel by weight in most conditions.
Annodizing can improve these two measurements (although, if I remember my classes, it's brittle so it'd help in compression not tension), but what we mostly care about is it changes the surface characteristics is improve the 'hardness' (likelihood of scratching for the most part) and changes its corrosion characteristics (eg, how it behaves in contact with acids).