NesC is same C???

The first time I heard the "NesC" word from my senior I think NesC may seem C programming.But after searching and learning some examples of NesC,I think NesC is not same C except basic commands.
NesC is developed from C but Why NesC is not same C? NesC is used to build applications for the TinyOS platform and running on sensor nodes.It is built as an extension to the C programming language with components "wired".
If you are a newcomer in the NesC language,there are 2 conceptions I think you feel difficult to understand.They are "components" and "interfaces".

• Components: a NesC application consists of one or more components assembled or wired to form an application executable.A component provides and uses interfaces.
• Interfaces:a set of commands and a set of events

the detail explanation of above conceptions at address: TinyOS Documentation