What's a partition? Help with fomatting sd card please

[learntojive]

Hi, I've starting messing with things I don't understand and got in a bit of a mess!
I'm trying to play some Mp3 songs on my Pure Evoke 3 from an sd memory card. I've done this before with an older memory card and never had any problems but the radio won't read it.
I've got to reading various forums it seems the card has to be formatted with FAT16?
I've followed some instructions for going into disc management and deleting the partion on my memory card and now neither my computer,the radio or my camera will recognise the card.
I need to know -
1. How to fomat in FAT16?
2. What's a partition?
3. Have I ruined my 4gb memory card?

I know I should have asked the question on here first before messing with it, I hope someone can help me, thanks x

[dothawkes31]

sharp intake of breath...........

[learntojive]

sorry ...typed that a bit quick, should say formatting!

[learntojive]

oh dear ...i knew I'd messed up!