Sage describes Sage 100 as ERP software for small and midsize businesses that manages core operations such as finance, accounting, sales, and reporting in one connected system.
It is built from modules. Financial modules include General Ledger, Accounts Payable, Accounts Receivable, and Bank Reconciliation. Distribution modules include Inventory Management, Sales Order, Purchase Order, Return Merchandise Authorization, and Bar Code. Manufacturing modules include Bill of Materials, Work Order, and Production Management, with planning through Material Requirements Planning or Inventory Requirements Planning.
Sage 100 is offered in Standard, Advanced, and Premium editions, which differ mainly in their technical architecture, with Premium running on Microsoft SQL Server. It is installed on-premises or hosted by a partner, and it is sold, implemented, and supported through Sage's partner network. Many companies extend it with third-party add-ons from that ecosystem.
That is important context. Sage 100 is a capable, proven system. The more useful question is whether a modular, add-on-based approach is still the best fit for how your business operates today.