Symbolize layer and group names in TOC?

What is group layer in ArcMap symbology?

A group layer contains other layers. Group layers help organize related kinds of layers in a map and can be used to define advanced drawing options. For example, suppose you have two layers on a map representing railroads and highways.

How do I fix table of contents in ArcGIS?

In some instances, the Table Of Contents displays as a tab at the top-left corner of the data frame view. To open the Table Of Contents, hover over the tab and click the Auto Hide button (pin symbol) located at the top-right corner, next to the Close button. This fixes the Table Of Contents to its location.
 

Does ArcMap draw the top layers in the table of contents first?

ArcMap displays geospatial data according to the order in the table of contents: the bottom layer will be drawn on the screen first and covered by upper layer. Hence, the layer on the top in the table of content will be displayed as the top layer in the map.