SAP Client concept
A client is a self-contained tenant within an SAP system, with its own master data, transaction data and customizing (to a degree). The client concept lets one physical system host several isolated environments, and it shapes how configuration and data are managed.
An SAP client is an isolated data partition inside one system, chosen at logon: business data in client 100 is invisible in client 200, which is how a DEV system holds a customising client, a sandbox and a test client. Repository objects such as programs and certain cross-client settings are shared by every client, so changing one affects them all.
- Watch out: Assuming everything is client-isolated, some objects are cross-client.
What a client is
When you log into SAP, you specify a client number. That client is an isolated data partition: business data in one client is invisible to another. This is how a single DEV system can hold a customizing client, a sandbox client and more, each isolated.
Client-dependent vs client-independent
A crucial distinction: some data and configuration are client-dependent (exist separately per client), while others, like most repository objects (programs) and certain cross-client settings, are client-independent (shared by all clients in the system). Changing client-independent objects affects every client, which surprises newcomers.
Typical clients
- Customizing client (configuration, captured in transports).
- Sandbox client (free experimentation).
- Test/training clients as needed.
Why it matters
Understanding clients prevents costly mistakes, like changing a cross-client object thinking it is isolated, and clarifies where your data and configuration actually live.
Common pitfalls
- Assuming everything is client-isolated, some objects are cross-client.
- Working in the wrong client.
- Confusing client with system or company code.