preamble
/ˈpriːˌæmbəl/
noun
plural
preambles
plural
preambles
Britannica Dictionary definition of PREAMBLE
somewhat formal
1
:
a statement that is made at the beginning of something (such as a legal document) and usually gives the reasons for the parts that follow
[count]
[noncount]
2
[count]
:
something that comes before and leads to something else