Examples of collateral documents are a security agreement, guarantee and collateral agreement, pledge agreement, deposit account control agreement, securities account control agreement, mortgage, and UCC-1s.
Suppose you agree to rent an apartment. The lease agreement you sign with the landlord is the main contract. However, your landlord promises to fix the toilet drainage. Therefore, this is the collateral contract.
The collateral sheet shows a comparison of the collateralization based on the maximum risk and the current risk for receivables. You can also use the collateral sheet to determine if the receivables have been collateralized appropriately (there is no excess or insufficient collateralization for the receivables).