Geoprocessing Tools || Intersect || Union || |Merge || Dissolve || in ArcMap

Intersect, Union, Merge, and Dissolve are geoprocessing tools in ArcMap used to manipulate spatial data.

Intersect: This tool combines two or more input layers and creates a new output layer that includes only the features that intersect with each other. For example, if you have a layer of roads and a layer of water bodies, the intersect tool can be used to create a new layer that only includes the portions of the roads that intersect with the water bodies.

Union: This tool also combines two or more input layers, but unlike the intersect tool, the output layer includes all the features from all input layers. For example, if you have a layer of cities and a layer of counties, the union tool can be used to create a new layer that includes all the cities and all the counties.

Merge: This tool combines two or more input layers into a single output layer. However, unlike the union tool, the merged layer will have only one set of attribute fields. For example, if you have a layer of streets and a layer of highways, the merge tool can be used to create a new layer that includes all the streets and highways with a single set of attribute fields.

Dissolve: This tool takes a layer with overlapping polygons and dissolves them into a new layer with non-overlapping polygons. For example, if you have a layer of parcels with multiple ownerships, the dissolve tool can be used to create a new layer with a single polygon for each parcel and a set of attribute fields that summarize the information for each parcel.