When you edit or delete a component definition, this influences all objects based on this component definition. Please check how many instances corresponding to the component definition exist in your network documentation before making any changes.
Instances are real network objects which you display and document in Pathfinder and which are always based on a component definition. Pathfinder shows you how many instances corresponding to a component definition exist in the section "detailled infomation".
If there are more than zero instances, you can click on the three dots (1) and a window will open that lists all intances of this component definition (2). To open an instance use double click.