User blog comment:Njalm2/Nanja's Grimoire: Abjuration/@comment-18812574-20160108152836/@comment-3403804-20160108181106

You more or less answered your own question there, Shonen. Protective abjurations typically last a while and can be placed on objects, locations and of course, people. Meanwhile a barrier is a stationary piece of constructed energy - at least in the typical Bleach sense, often made to assume geometric shapes such as boxes, spheres or walls.

An abjuration can for instance, make an object completely undetectable by means of the spiritual senses, and do the same with an individual. In the case of Abjuration, this effect would persist until dispelled or it dissipated on it's own - whereas a barrier who conferred these advantages would cease to do so immediately upon exit. Wards are all very similar to Millon Escudo, although most of them are assigned to an entire person, as opposed to a specific point like with Millon Escudo, which was a rather primitive if still supremely effective ward.

Characters like Fumio and Kazuya customize their wards to great degrees to complement their approach to fighting, whereas someone like Hiroya uses a very simple ward, even if it is refined to the point of absolute perfection.

Anyway, in most cases, Wards are indeed capable of being used in all manners of different forms, although Abjuration on it's own is fairly limited in this regard, such a ward is always going to be a tool of protection. Kazuya combined the schools of Abjuration and Evocation to create the ward known as Amaterasu's Benediction, for instance.