The term pH stands for 'potential of Hydrogen' and it is a measure of the acidity or basicity of an aqueous solution. The pH scale ranges from 0 to 14, with 7 being neutral. A pH lower than 7 indicates acidity, while a pH higher than 7 indicates alkalinity. The human body tightly regulates its internal pH levels for optimal biochemical processes. For instance, blood typically maintains a pH around 7.4.