A transparent sphere of protective magic surrounds you until the spell ends. For the duration, you are considered to have Half Cover, which grants +2 to AC and Dexterity Saving Throws. The cover produced by this spell overlaps with other sources of cover, such as trees and low walls.

You can also grant yourself Three-Quarter Cover until the start of your next turn as a Reaction¹, including against the triggering attack/effect, although doing so ends the spell. 

¹ - which you take when you are hit by an attack or included in the effect of a spell.