Refreshes the table of contents.
If Python is used to modify the table of contents within the current map document (e.g., change a layer name), the map will not automatically update with the changes. RefreshTOC is only needed if you want to see the table of contents updated.
A simple script run from the Python window that demonstrates how to update the Table of Contents and force a refresh to make the change visible.
# Create a MapDocument object from the current map
mxd = arcpy.mapping.MapDocument("CURRENT")
# Update the layer name of the first layer in the Table of Contents
arcpy.mapping.ListLayers(mxd).name = "New Layer Name"
# Refresh the Table of Contents to reflect the change