The fields are the data containers in the scene graph. Nodes and engines all use fields to store their public data.

Fields can be inter-connected, causing changes at one location in a scene graph to cause other parts of the scene graph to automatically also get updated. Direct field-to-field connections will cause values to get duplicated, while field connections together with engines can create complex networks for such updating that include mathematical computations and logical operations. Field connections are uni-directional, but setting up a connection in both directions will cause a bi-directional connection.

Fields are first divided into two groups; "single fields" and "multi fields". Single-fields contain just one value, while multi-fields can contain many values or even none at all.

Besides fields that are part of nodes, you also have "global fields". The "realtime" field is one such field.

The fields in VRML97 nodes have additional semantics. Some are "event_in" and some are "event_out", listening for events or triggering events. "event_in" events should not be read from, and "event_out" fields should not be written to.