Ok, but does that mean that the voltage will always be 5.6v?
No.
I understand that it will limit it to 5.6v but will it let any less than that through? does it have to get to atleast5.6v before it will let any electricity pass?
No.
Also do I have to use a resistor?
Yes.
if I am happy for whatever ampage the solar panel produces to be passed through or does it have to be there?
what resistor would I have to use if I wanted it to be restricted to say 300ma? how would i work it out? sorry for all the questions but I have a lot to learn.