GP offers utilities to conduct data integrity checking and reconciling data. Check Links would detect such as things data in one table that should be in another, but isn't; for example, if a sales transaction detail record existing in the sales transaction line table, but didn't have a corresponding sales transaction header record in the header table. Reconcile tends to differ in the sense that it validates existing business data; for example, with inventory if a given item in GP had quantity on hand of 10, quantity allocated of 8 (yielding a quantity available of 2), inventory reconcile will validate that this is actually correct by looking at the cost layers and posted inventory transactions to validate that 10 is truly what is on hand and that the quantity allocated of 8 is what is actually on unposted transactions (for example, an open sales transaction for 8 units would mean there are 8 units allocated not yet shipped so haven't yet been removed from inventory).