The picture below is a common brick with a flushed mortar joint, which is very common to the original construction here in Capitol Hill.
The following picture is a concave mortar joint which is very common to typical construction in tract homes in modern construction outside of the city. This particular picture is in Capitol Hill, but at a newly-renovated and rebuilt area of masonry for a commercial condo building, NOT historic construction.
The following pictures shows a raked joint and a modern concave joint side-by-side.
The following diagram shows an assortment of different styles of mortar joints. Each is struck in a different style.