What is the relationship between basicity and nucleophilicity in organic chemistry?

In organic chemistry, basicity and nucleophilicity are related but not always the same. Basicity refers to the ability of a molecule to accept a proton, while nucleophilicity refers to the ability of a molecule to donate an electron pair. Generally, molecules that are basic are also nucleophilic, but there are exceptions due to factors like steric hindrance and solvation effects.