Overlay analysis is one of the fundamental spatial operations in GIS, referring to the process of generating new data through set operations between vector datasets. The application provides overlay analysis functions for point, line, and polygon datasets, including clip, union, erase, intersect, identity, symmetric difference, and update.

• Overlay Analysis Overview: Detailed introduction to the basic concepts of overlay analysis and related logical operations.
• Overlay Analysis Tools: Comprehensive explanation of the basic concepts and principles of seven overlay analysis tools.
• Clip: Clip operation extracts a subset of features (points, lines, or polygons) from the source dataset using the overlay dataset (clip dataset).
• Union (Merge): Union operation performs a union between the source dataset and overlay dataset.
• Erase: Erase operation removes features from the source dataset that overlap with the overlay dataset (erase dataset).
• Intersect: Intersect operation retains the overlapping areas between the source dataset and overlay dataset (intersect dataset).
• Identity (Same): Identity operation performs an intersection between the source dataset and overlay dataset.
• Symmetric Difference (XOR): Symmetric difference operation preserves features from both datasets that do not overlap.
• Update: Update operation replaces overlapping areas in the source dataset with features from the overlay dataset (update dataset).