What is the base rate in the UK?

Could you please elaborate on the concept of the base rate in the United Kingdom? I'm interested in understanding its definition, how it's determined, and what factors influence its fluctuations. Also, how does the base rate impact the overall economy and individual borrowers and savers? Is it adjusted periodically by the central bank? Finally, how does it differ from other types of interest rates in the UK financial system? Thank you for shedding some light on this matter.