What is a DLL?

What is a DLL?
A DLL is a library that contains code and data that can be used by more than one program at the same time. For example, in Windows operating systems, the Comdlg32 DLL performs common dialog box related functions. Therefore, each program can use the functionality that is contained in this DLL to implement an Open dialog box. This helps promote code reuse and efficient memory usage.
https://support.microsoft.com/en-us/kb/815065

Bill of quantities

• Bill of quantities

A bill of quantities (BOQ) is a document used in tendering in the construction industry in which materials, parts, and labor (and their costs) are itemized. It also (ideally) details the terms and conditions of the construction or repair contract and itemizes all work to enable a contractor to price the work for which he or she is bidding.
http://en.wikipedia.org/wiki/Bill_of_quantities

• An itemized list of materials, parts, and labor (with their costs) required to construct, maintain, or repair a specific structure.

http://www.businessdictionary.com/definition/bill-of-quantities-BOQ.html