ZBrush works with millions of polygons at once, so artists can push a model from a rough blockout to fine surface detail without switching programs. Its brush system covers everything from broad form changes to small wrinkles and scales. DynaMesh and ZRemesher help keep geometry clean while you sculpt.
Studios use it to make characters, creatures, props, and printable figures. Finished sculpts usually move into Maya, Blender, or a texturing tool for retopology, UVs, and rendering. It has a steep learning curve and an unusual interface, which new users tend to find odd at first.
Maxon owns ZBrush and sells it by subscription or as part of a bundle. Blender sculpt mode and Nomad Sculpt are the usual alternatives. ZBrush suits character artists and anyone who sculpts for a living.