Can you explain the difference between 'product cash' and 'model cash'?

'Product cash' means any cash held in the product Cash Account.

'Model cash' is cash held in a model portfolio. A model portfolio is treated as an asset in its own right. It can be added to the account’s asset allocation, where a percentage is specified. You can have all of the account invested in the model, or just a portion. You can also assign more than one model to an account. Any cash allotted to the model is there for asset allocation purposes and can't be used to fund charges and withdrawals. Where there is no product cash available within the account, the system will sell down proportionately from the model assets.