(Wikipedia excerpt: …”…connector/s/ion (C)…When using glassware it is often necessary to control the flow of fluid. It is commonly stopped with a stopper. Fluid may be transported between (C) pieces of glassware. Types of interconnecting components include glass tubing, T- (C), Y- (C), and glass adapters. For a leak-tight (C) a ground glass joint is used (possibly reinforced using a clamping method such as a Keck clips).
Another way to (C) glassware is with a hose barb and flexible tubing. Fluid flow can be switched selectively using a valve, of which a stopcock is a common type fused to the glassware. Valves made entirely of glass may be used to restrict fluid flows. Fluid, or any material which flows, can be directed into a narrow opening using a funnel….”)