what is the diff between properties in indexer in c#?

Indexers always have the same name as the type itself and, unlike properties, always take parameters. The parameters are passed in square brackets as if the indexer were an array.

There can be a single or multiple parameters separated by commas.

Indexers are declared using the 'this' keyword.

For more details and an example check this link:

http://msdn.microsoft.com/en-us/library/6x16t2tx.aspx