A .WRZ file is usually a gzip-compressed VRML world, meaning it’s just a .WRL 3D scene shrunk to reduce size, since VRML is a text-based format describing full 3D environments—geometry, materials, textures, lights, and sometimes animation—so compressing it works extremely well, and systems label this compressed form as .WRZ or sometimes `.wrl.gz`, with the typical workflow being to decompress it using tools like 7-Zip or `gzip` to get a .WRL file that VRML-capable viewers can load, keeping texture files in their expected folders so they appear correctly.

A straightforward check is verifying whether the file starts with the hex prefix 1F 8B, a strong sign of gzip compression matching the WRZ format, and a common misunderstanding is mixing it up with RWZ, which belongs to email filtering rule backups, so if the file came from email migration it may be RWZ, whereas anything from a 3D or CAD workflow is usually a true WRZ.

When someone says a .WRZ is a "Compressed VRML World," they mean that a standard VRML scene file—usually .WRL, literally short for *world*—has been gzipped to reduce space, since VRML uses structured text to describe full 3D scenes like geometry, materials, textures, lights, viewpoints, and basic behaviors, and because text compresses so effectively, the community adopted .wrl.gz and .wrz to indicate a gzipped VRML file.

From a practical standpoint, the phrase "compressed VRML world" signals that you should treat the file as a gzip archive first to recover a .WRL usable in VRML/X3D-capable software, and you can verify this by checking for gzip’s magic bytes the code 1F 8B in a hex viewer, which is strong evidence you’re dealing with an authentic gzipped VRML file, not a look-alike format.

Inside a VRML "world" (the .WRL recovered after decompressing a .WRZ) you’ll usually see a scene graph of typed nodes describing both what appears on screen and how you move through it, with Transform/Group nodes shaping a hierarchy of position/rotation/scale, Shape nodes pairing geometry like Sphere with material/texture settings via Material and ImageTexture, and additional world elements such as Viewpoint for camera jumps, NavigationInfo for movement style, and bindable environment nodes like Background, Fog, or Sound for ambience.

VRML’s interactivity uses Sensor nodes like event sensors to send events, animations build on TimeSensor plus the Position/Orientation/Color/Scalar interpolators that provide time-based outputs, and ROUTE links connect everything, while complex behaviors rely on Script nodes with VRMLScript/JavaScript or occasional Java, and Anchor nodes allow hyperlink-like navigation, with the specification distinguishing transform-affected nodes from non-spatial ones such as interpolators, NavigationInfo, TimeSensor, and Script, giving the world the character of a small interactive program rather than a simple 3D model.

The phrase "Compressed VRML World" for .WRZ indicates that WRZ isn’t a separate 3D type but a normal VRML .WRL scene that’s been reduced through gzip to make distribution smaller, preserving the VRML text that defines meshes, textures, lights, cameras, navigation, and basic interactivity, wrapped in gzip with typical extensions .wrz or .wrl.gz, a convention cited by the Library of Congress; that’s why tools like 7-Zip/gzip open it, and why checking for gzip’s magic bytes the 1F 8B prefix is a good sanity check.