DOF or depth of field is the depth range that is focused, it increases as you stop down the aperture: F2.8 shallow DOF, F16 deep DOF.
Bokeh is a japanese term and refers to how out of focuse items appear on the photo. The aperture blades do play a role in that. Out of focuse spot like objects tend to be shaped by the opening created by the aperture blades. We have all seen reflections created by spot lights or the sun when taking a photo i direction of the sun. The reflection are caused by the lenses but the shape of the reflection is governed by the aperture blades, if the lense has only 6 blades, the spots are not round but rather hexagonal. Now the less polygonal and more round the shape of the out-of-focuse object appears the better the bokeh.
Bokeh is also affected by the lense construction itself, how sharp the lense is reproducing and by how things go out of focuse