What do the order statuses mean for my orders?

Processing = order has been received and paid for.

Pending payment / pending deposit payment = order received and items reserved but awaiting payment.

On hold = order received and items reserved but awaiting payment.

Completed = order paid for and dispatched from us.

Partially paid = order received and deposit paid.  Balance to be paid in future (not yet due).

Scheduled = automatically scheduled payments (due on scheduled due date)