I wonder what to write… There I knew, it’s about a Base:
NOUN 1. The lowest part or edge of something, especially the part on which it rests or is supported; 2. A conceptual structure or entity on which something draws or depends; 3. A place used as a centre of operations by the armed forces or others as a headquarters; 4. A main or important element or ingredient to which other things are added; 5. Chemistry: A substance capable of reacting with an acid to form a salt and water, or (more broadly) accepting or neutralizing hydrogen ions; 6. Electronics: The middle part of a bipolar transistor, separating the emitter from the collector; 7. Linguistics: The root or stem of a word or derivative; 8. Mathematics: A number used as the basis of a numeration scale; 9. Baseball: Each of the four stations that must be reached in turn to score a run.