Standard Fit vs Comfort Fit

Standard Fit

Also known as flat fit rings, standard fit rings are a traditional style known for their classic profile. The interior of the ring is flat, resulting in a snug fit.
standard fit wedding ring profile

Comfort Fit

As the name suggests, comfort fit rings curve away from the finger offering ease of wear as they allow the ring to slide more easily on and off the finger. 
comfort fit wedding ring profile