1) In general, an intermediary is a person or service that is involved as a third party between two or more end points in a communication or transaction.n the World Wide Web, the role of an intermediary is sometimes said to be no longer necessary as, for example, when you look up legal or medical information directly yourself or when you share files with other Internet users directly (see peer-to-peer).
A roof covers a building or home structure, protecting any belongings found within. There are a large number of materials that can be used to roof a building or home, including several types of metal roofing materials. These materials include steel, aluminum, copper and tin.
The most common original roofing material is tar and gravel. A tar and gravel roof consists of layers of asphalt and tar paper (or newer, more sophisticated materials) adhered with applications of molten asphalt. The laminated layers get a top finish of gravel, some of which becomes embedded in the hot asphalt, and some of which lays loose on the surface of the roof.