What's the meaning of "|" and "@" in C#?

[C# Programming]

Dear All:

Could anyone give me some useful articles about introducing the symbol "|" and "@" in C# please?

For example, I saw a code something like:


FileSystemWatcher fsm = new FileSystemWatcher(Environment.GetEnvironmentVariable("USERPROFILE"));

fsm.NotifyFilter = NotifyFilters.FileName | NotifyFilters.LastWrite;


ThanksAsura