Total amount for small claims?

You can claim up to £100,000 via MCOL.

The different values relate to which track it is likely to be allocated to. The general rule is that claims worth less than £10k (unless they are particularly complex or possibly contain human rights issues) will be allocated to the small claims track. £10-25k is usually allocated to fast track and £25k+ is usually allocated to multitrack. The court has discretion, so a very simple debt claim for £10,500 could still ultimately end up in small claims.

The difference between small claims and the other tracks is the procedure. You are more likely to have directions hearings outside of small claims. You are also likely to have to deal with disclosure, plus a myriad of other procedural rules that will have to be abided by. Also, the court is less forgiving outside of the small claims track. Also, costs outside of small claims can be extensive and sometimes determining costs can be the subject of a hearing of its own. Also, if you get things wrong, you may end up winning you claim but having an adverse costs order (i.e. you have to pay the other sides costs) and these costs may only be slightly less (or even more) than your damage award.