The Microsoft Update Catalog is a searchable catalog of all security updates, drivers and service packs that are available through Windows Update (WU) and Microsoft Update (MU). You can also use the Microsoft Update Catalog to obtain and deploy hotfixes. You can use the Microsoft Update Catalog to distribute these updates through a corporate network using tools such as WSUS 3.0, System Center Essentials (SCE) or System Center Configuration Manager (SCCM).
The Microsoft Update Catalog expands the capabilities of your update deployment infrastructure and provides the capability to deploy hotfixes to address known issues in security updates when they occur. We encourage all who are using WSUS 3.0, SCE or SSCM to evaluate the Microsoft Update Catalog for their environment.
More info: Microsoft Update CatalogMicrosoft, Windows, Updates, Microsoft Update Catalog, Searchable Catalog, Security Updates, MSRC