Standard assemblies are those that can be inserted into projects.  The comprise a library of designs for future use.  For example you can create a book case, save it as standard, and call it into another design.

 

The standard object is inserted to the location you specify in the same location as the original.  So if the original object had a left - front - bottom values of 10 - 20 - 10, the inserted object will be placed with its point of origin at 10 - 20 - 10.