For more details, read this blog “Contract and Convention: How these two are different” Perhaps because of its popularity with newspaper editors, which has gained its brevity for it, the pact is used with increasing frequency in the (often unofficial) title of agreements between states; in this use, it is often exchanged with the treaty, which is the generic term of an agreement between states concluded through negotiation or diplomacy. A convention is usually an agreement that is either less formal or more specific than a treaty; It can be an agreement between several states that regulates issues that concern all these issues (such as postage, copyright or war) or an agreement between army commanders on military operations.