OK, the solar panels generate a direct current (DC), whereas all of our household appliances etc operate on an Alternating Current (AC).
The solar panels generate electricity and then that is used to charge up the 12v batteries (simple car/leisure batteries), via a solar controller which if you look at the kits I referenced, is all included as part of the kit with the Solar panels.
The invertor therefore takes the 12v DC electricity which is stored in the batteries and then converts it to an 240v AC supply on which you can run your electrical equipment.
This is an invertor and the crocodile clips connect straight onto the battery and then you can plug in your electrical equipment via the 3 pin socket on the invertor:
http://www.amazon.co.uk/gp/product/B00DI...ge_o00_s00
Leisure battery:
http://www.amazon.co.uk/Leisure-Battery-...re+battery
Others may give you a more technical (accurate) interpretation