Answer:
And unless people interfere, thermal energy — or heat — naturally flows in one direction only: from hot toward cold. Heat moves naturally by any of three means. The processes are known as conduction, convection and radiation. Sometimes more than one may occur at the same time.
If she has a choice and the wiring details are stated on the packaging,
then Janelle should look for lights that are wired in parallel within the
string, and she should avoid lights that are wired in series within the string.
If a single light in a parallel string fails, then only that one goes out.
The rest of the lights in the string continue to shimmer and glimmer.
If a single light in a series string fails, then ALL of the lights in that string
go out, and it's a substantial engineering challenge to determine which light
actually failed.
