Tenant
In plain terms
An isolated customer instance within shared infrastructure.
Going deeper
A tenant is a customer's logically-separated space in a multi-tenant system, keeping data and config isolated from others. It's core to SaaS architecture.
Under the hood
Multi-tenancy shares infrastructure while isolating tenants via partitioning or per-tenant resources; isolation strength varies.
Examples
SaaS apps, Azure AD tenants, multi-tenant databases, customer isolation.
Think of it like...
Like separate apartments in one building, each private but sharing the structure.