A .WRZ file is effectively a gzipped VRML world, where a .WRL 3D scene—built from plain-text instructions describing geometry, materials, textures, lights, and occasional animations—has been compressed tightly for easier sharing, which resulted in the convention of calling such files .WRZ or `.wrl.gz`, and the usual approach is to unzip them with tools like 7-Zip or `gzip` to obtain a .WRL file that VRML-supporting viewers can load, with textures appearing correctly only if their referenced image files stay in the proper folders.

A reliable sanity check is looking for the gzip marker 1F 8B, which strongly hints the file is a compressed stream consistent with WRZ, and one common mix-up involves RWZ, a format tied to Microsoft Outlook’s Rules Wizard, so email-origin files are likely RWZ, while assets from 3D or web-3D workflows are usually proper WRZ files.

The phrase "Compressed VRML World" for a .WRZ indicates that it’s a VRML scene file—typically a .WRL, with "WRL" meaning *world*—that has been packed using gzip to reduce its footprint, because VRML uses structured text to define entire 3D scenes including geometry, materials, textures, lights, and interactive elements, and this text compresses very efficiently, so the VRML ecosystem commonly labels gzipped VRML as .wrl.gz or .wrz.

Practically speaking, calling it a "compressed VRML world" tells you to handle the file like a gzip stream first so it can expand into a .WRL readable by VRML/X3D-compatible tools, and one easy technical check is whether the file begins with the gzip signature 1F 8B, which strongly indicates you’re dealing with a real gzipped VRML file and not a different format that only looks similar by extension.

Exploring a VRML "world" (the .WRL you get from unpacking a .WRZ) shows a scene graph of typed nodes describing visuals and user movement, with Transform/Group constructs managing transform hierarchies, Shape nodes merging geometry such as Extrusion with Material/ImageTexture appearance, and standard world components including Viewpoint cameras, NavigationInfo behavior settings, and bindable environment nodes like Background, optional Fog, and Sound.

Interactivity in a VRML world is handled through Sensor nodes like TouchSensor that emit events, while animation is driven by TimeSensor plus Position/Orientation/Color/Scalar interpolator nodes that output changing values over time, all connected using ROUTE links (eventOut → eventIn), and more complex behavior comes from Script nodes using VRMLScript/JavaScript or sometimes Java, along with Anchor nodes for hyperlink-style jumps, with the spec separating transformable nodes in the hierarchy from non-spatial nodes like interpolators, NavigationInfo, TimeSensor, and Script, which is why a VRML world behaves like a small interactive program rather than a simple mesh.

Calling a .WRZ a "Compressed VRML World" means the file isn’t a unique format but a standard VRML world (.WRL) stored as gzip to shrink download/storage size from the early web-3D period, leaving the VRML text intact—shapes, textures, lights, viewpoints, navigation, and simple behaviors—just packaged in gzip and signaled with .wrz or .wrl.gz, as noted by references like the Library of Congress, which is why 7-Zip/gzip opens it and why identifying the gzip 1F 8B bytes helps confirm it’s really gzipped VRML.