TinyOWS is a lightweight and fast implementation of the OGC WFS-T specification. Web Feature Service (WFS) allows querying and retrieval of features. The transactional profile (WFS-T) allows inserting, updating or deleting such features.

From a technical point of view WFS-T is a Web Service API in front of a spatial database. TinyOWS is deeply tied to PostgreSQL/PostGIS because of this.

TinyOWS implements strictly OGC standards and pass successfully all WFS OGC CITE tests (and even beta ones).

TinyOWS is part of MapServer Suite, but provided as a distinct module (i.e you could use it in conjunction with MapServer and MapCache, or as a standalone app). But both MapServer and TinyOWS could use the same configuration file, if you want to (or native TinyOWS XML config file).