Self-reg Heat cable, 120V 10 watts per ft, jacketed UL

Heat tape is electrical equipment: improper installation, damaged cable, or misuse can cause fire or electric shock. Select cable approved for your pipe and location, follow its layout and insulation requirements, provide the specified electrical protection, and inspect it before each cold season. Do not use damaged equipment or overlap cable unless the exact product instructions permit it.

Yes, it can be used for both application types to prevent pipes from freezing and bursting during cold weather.

Heat trace, heat tape, or heating cable for pipes is typically an electric heating cable that can be attached to the pipe which helps keep non-flowing water pipes in poorly insulated perimeter walls flowing despite harsh winter temperatures.

Pipe heat tape is intended for freeze prevention, not as a guaranteed way to thaw an already frozen pipe. A frozen pipe may be damaged. Have the plumbing assessed and thawed safely by a qualified professional; never use an open flame. Before future cold weather, verify cable selection, thermostat placement, insulation, and electrical protection.

By attaching a heating cable to the exterior of a pipe, it will transfer the heat to the pipe to prevent frozen pipes. And with the use of pipe insulation the heat will be evenly spread and won't dissipate as quickly.

No.  It is not listed for this application, and it is not warrantied for use in direct burial or wet applications.