Under international law, a ceasefire is a legal agreement (often in a document) that puts an end to fighting between the “belligerents” of war or conflict.  In the Hague Convention of 1899, in which three treaties were concluded and three declarations were made, the Convention on the Laws and Customs of War in Rural Areas established that “if the duration of the ceasefire is not fixed”, the parties can resume fighting (Article 36) at their convenience, but with correct communications. It is a “fixed-term” ceasefire, where the parties can only renew the fighting at the end of their fixed duration. If the belligerents say (in fact) “this ceasefire puts a complete end to the fighting” without a ceasefire deadline, then the duration of the ceasefire is set in the sense that no resumption of fighting is allowed at any time. Thus, the Korean ceasefire agreement calls for a “ceasefire and ceasefire” and aims to “achieve a ceasefire that guarantees a complete cessation of hostilities and all armed acts in Korea until a definitive peaceful solution is found.  Ceasefire agreements can take place between state actors if they can even reach the stage of a global ceasefire or involve non-state actors and be “local”.  They may be formal (usually in writing) or informal; their conditions may be public or secret. Ceasefires can be carried out by mediation or otherwise as part of a peace process, or by United Nations Security Council resolutions on Chapter VII of the United Nations Charter.  The cessation of hostilities is broader and more formal than a ceasefire, but not quite a ceasefire agreement. One or both sides say they will suspend the fighting as a whole. The cessations are generally conceived as the beginning of a major peace process, but they are temporary and non-binding, and in a conflict involving many parties, such as the civil war in Syria, the attitude can only apply to a few opponents.
A ceasefire (or ceasefire) that has also concluded a ceasefire (the anonymity of “open fire” ) is the temporary end of a war in which each side agrees with the other side to suspend aggressive actions.  Historically, the concept existed at least in medieval times, when it was known as the “peace of God.”  Ceasefires may be declared as a humanitarian gesture provisionally, i.e. before a political agreement, or definitively, i.e. for the purpose of resolving a conflict.  Ceasefires can be declared as part of a formal treaty, but they have also been described as an informal agreement between opposing forces.  Strictly speaking, a ceasefire is an informal cessation of fighting.