A community style nest box does not have any walls or dividers in the laying area.  The laying area is one continuous open space.   This differs from divided nest boxes that have walls/dividers between the spaces where hens lay.  Divided nest boxes are often referred to by the number of spaces(also called "holes") that the nest box contains- 4-hole, 8-hole, 10-hole, etc.  In  divided nest boxes, chickens often try to crowd each other out in the individual spaces.  You can often have a particular space that becomes a favored place where multiple hens will cram in while leaving other spaces empty.  A community style nest box helps alleviate this issue.  In fact,  many commercial egg operations use community style boxes.  The Best Nest Box is a community style nest box  and was the first community style roll out nest box to hit the market in 2003.