Layman - (noun) - 1: a person who is not a member of the clergy; 2: a person who does not belong to a particular profession or who is not expert in some field.
Figure 1 Figure 2.
String theory is quite fascinating if you are not a layman in quantum mechanics (see figure 1). If you are layman in quantum mechanics, then figure 2 makes more sense.
For more information - https://www.dictionary.com/browse/layman?s=t
For more information on String Theory - https://en.wikipedia.org/wiki/String_theory