It is based on observable, empirical, measurable evidence, and subject to laws of reasoning, both deductive and inductive.
The most traditional data structure used for organizing the subfields of science is the "tree of knowledge", hence the idea of different scientific "branches".
But over time, several other taxonomic systems have also been proposed for that purpose (such as networks, tables or circular schemes).
Validity, accuracy, and social mechanisms ensuring quality control, such as peer review and repeatability of findings, are among the criteria and methods used for this purpose.
'Social' is the concept of exchange/influence of ideas, thoughts, and relationship interactions (resulting in harmony, peace, self enrichment, favoritism, maliciousness, justice seeking, etc.)