What are higher alkyl sulphates and how are they used in cleaning products?

[danago]

Hey.
I was looking at the chemicals in a certain cleaning product, and there was one that i am unfamiliar with (and couldn't really find relevant information about). The product has been claimed to contain "Higher alkyl sulphates". What does this refer to? What are alkyl sulphates, and what does the "higher" refer to?

Thanks in advance.
Dan.

PS. I am a first year engineering student and have yet to take any chemistry units, so my chemistry knowledge doesn't go past high school chem.

 

[GCT]

It is probably in reference to the carbon number.