Hi Charles,
Trust Accounting is used in where an organisation is managing someone else money, ie legal firm, or a property management company. Trust Accounts are usually regulated
For example, suppose you bought an apartments, and signed up a property management company to manage the property on your behalf. The tenant would pay the rent into the trust account, and any expenses would need to be paid out of the trust account.
In a legal firm - any monies a client pays to a lawyer to defend a court case or to prepare for a court case are paid into a Trust Account. All withdrawals from the client trust account have to be recorded and fully auditable. If this is not done, the lawyer can be disbarred and face criminal proceedings.
Hope this brief explanation helps