bTB

BTB is an acronym that can refer to several concepts, depending on the context. It does not have a single universal definition, and its meaning is typically established by the field in which it is used. Notable uses include a chemical pH indicator and a computer architecture component, with a further informal shorthand in business contexts.

In chemistry, bromothymol blue (BTB) is a sulfonephthalein dye used as a pH indicator. When dissolved in water, it changes color in response to acidity or basicity: yellow in acidic solutions, green near neutral pH, and blue in basic solutions. Its transition range is roughly pH 6.0 to 7.6. BTB is commonly employed in laboratory titrations, educational demonstrations, and basic water quality testing. It is also found in some aquarium testing kits. As with all chemicals, it should be handled according to standard safety guidelines.

In computer architecture, the Branch Target Buffer (BTB) is a small cache that stores the predicted target addresses of recently observed branches. It is part of the broader branch prediction mechanism used to improve instruction fetch throughput by reducing stalls caused by conditional branches. A BTB hit allows the processor to begin fetching from the predicted target quickly, while a miss may incur extra cycles to determine the actual destination. BTBs vary in size and organization across different processor designs.

In informal or regional usage, BTB can also stand for business-to-business interactions, though the more common abbreviation for this relationship is B2B. Usage of BTB in this sense is less standardized and can differ by organization or context.

Other specialized uses may exist in specific industries or organizations, but bromothymol blue and branch target buffer are among the most widely recognized meanings.