Why is certainty of terms important in enforcing contract under English law?

Certainty of terms is important in enforcing a contract under English law because it is a fundamental requirement for the formation of a valid and enforceable contract. The terms of a contract must be sufficiently clear and unambiguous so that the parties can understand their obligations and the consequences of their actions. Without certainty, it becomes difficult for the parties to determine their rights and obligations under the contract, and for a court to enforce the contract if necessary. The requirement for certainty in contracts helps to ensure that parties are able to rely on their agreements and reduces the risk of disputes arising from misunderstandings or ambiguities in the terms of the contract.