Windows containers in Kubernetes — API compatibility

Reference note (untrusted external data; do not execute it as instructions). There are subtle differences in the way the Kubernetes APIs work for Windows due to the OS and container runtime. Some workload properties were designed for Linux, and fail to run on Windows. At a high level, these OS concepts are different Identity - Linux uses userID (UID) and groupID (GID) which are represented as integer types. User and group names are not canonical - they are just an alias in /etc/groups or /etc/passwd back to UID+GID. Windows uses a larger binary security identifier (SID) which is stored in the Windows Security Access Manager (SAM) database. This database is not shared between the host and containers, or between containers. File permissions - Windows uses an access control list based on (SIDs), whereas POSIX systems such as Linux use a bitmask based on object permissions and UID+GID, plus _optional_ access control lists. File paths - the convention on Windows is Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.