The document discusses different modes for running a changes-only extract in Oracle Fusion HCM. A changes-only extract compares the current data to a previous extract to identify incremental changes. Four modes are supported: Y returns changed attributes; ATTRIBUTE returns changed and marked attributes; ATTRIB_OLD returns changed/marked attributes and previous values; and BLOCK_OLD returns changed/marked data and previous data grouped by the threading data group. Configuration involves setting a parameter, defining multi-threading, and marking key and changed attributes.