It's interesting that most of the comments are that the dry wall is coated. Around here, at least the non luxury houses, the joints are taped and the screws covered, but no final coat is applied.
Finish and coating are going to depend on how it is specified in the construction documents. There are five different levels to drywall finishing, most residential dry-wallers never go beyond level 2. Commercial jobs usually require more due to the expanse of some of the walls. For example, a level 2 finish on a long corridor in a hospital wouldn't work because the lighting reflected off the wall would make the tape seams more visible. I work for an architectural firm that does a lot of retail and other large commercial projects as well as medical/hospital projects and we rarely specify anything lower than a level 4 finish.
LEVEL 1 - Tape set in joint compound. Tool marks and ridges acceptable. Surface is free of excess joint compound.
Suggested use: Frequently specified in areas above ceilings, in attics, in areas where the assembly would generally be concealed, or in areas not normally open to public view. Some degree of sound and smoke control is provided. In some geographic areas, this level is referred to as "fire-taping". Tape and fastener heads need not be covered with joint compound.
LEVEL 2 - Tape embedded in joint compound and wiped with a joint knife, leaving a thin coat of compound over tape. Surface shall be covered by one separate coat of joint compound. Surface shall be free of excess joint compound. Tool marks and ridges acceptable. Joint compound applied over the body of the tape at the time of tape embedment shall be considered a separate coat of joint compound and shall satisfy the conditions of this level.
Suggested use: Specified where water-resistant gypsum backing board is used as a substrate for tile. May also be specified in garages, warehouse storage or other similar areas where surface appearance is not of primary concern.
LEVEL 3 - Taped as in level #2, then covered with two separate coats of joint compound. Joint compound shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: Typically specified in appearance areas which are to receive heavy or medium texture finishes before final painting, or where heavy-grade wall coverings are to be applied as the final decoration. This level of finish is not recommended where smooth painted surfaces, or light to medium weight wall coverings are specified.
LEVEL 4 - Taped as in level #2, then covered with three separate coats of joint compound. Joint compound shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: This level should be specified where flat paints, light textures or wall coverings are to be applied. In critical lighting areas, flat paints applied over light textures tend to reduce joint photographing. Gloss, semi-gloss and enamel paints are not recommended over this level of finish. The weight, texture and sheen level of wall coverings applied over this level of finish should be carefully evaluated. Joints and fasteners must be adequately concealed if the wall covering material is lightweight, contains limited pattern, has a gloss finish or any combination of these features is present. Un-backed vinyl wall-coverings are not recommended over this level of finish.
LEVEL 5 - Taped as in level #4. Surface shall be covered by three separate coats of joint compound. A thin skim coat of joint compound, or a material manufactured especially for this purpose, shall be applied to the entire surface. The surface shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: This level of finish is highly recommended where gloss, semi-gloss, enamel or non-textured flat paints are specified, or where severe lighting conditions occur. This highest quality finish is the most effective method to provide a uniform surface and minimize the possibility of joint photographing and of fasteners showing through the final decoration.