Reclassification is the process of reassigning one or more values in a raster dataset to new output values. The Reclassify tool is available in the Spatial Analyst extension in both ArcMap and ArcGIS Pro. If you are used to working with ArcMap, there are some noticeable differences in the Reclassify workflow in ArcGIS Pro. Here is a blog post about the best practices of using the Reclassify tool in ArcGIS Pro Spatial Analyst extension, especially when migrating from ArcMap.
Reclassify Raster Data in ArcGIS Pro Spatial Analyst Extension