Construction projects highly depends on typical installation details and drawings. Architects and engineers use this kind of information to reduce their work load. Employees particularly technicians and foremen who execute the project uses typical drawings as general guidelines where repeated structure, forms, shapes, operations, loads, etc. come into force.
A high rise building will have many identical floors say floors 3 to 10 are identical in structure, shapes etc. In such cases, design team will issue details and drawings for only one floor mentioning typical for so and so floors.
On the other hand, a particular installation can be used to many different projects having different structure, forms, shapes etc. also use typical details and drawings, eg., electrical earthing, installation of utility fixtures etc.