Treaties are also referred to as international conventions, international agreements, covenants, final acts, charters, protocols, pacts, accords, and constitutions for international organizations. Usually these different names have no legal significance in international law.
Treaties may be bilateral (two parties) or multilateral (between several parties).
A treaty is usually only binding on the parties to the agreement. An agreement "enters into force" when the terms for entry into force as specified in the agreement are met.
Treaties usually follow the same general process: adoption - signature - ratification. Each country follows its own ratification procedures, after which the ratification instruments are exchanged or deposited with a depositary.
In the United States, ratification generally takes the following path: Executive branch negotiates and signs treaty - President submits treaty to Senate - Senate prints proposed treaty (S. Treaty Doc. No.) - Senate refers proposed treaty to Senate Foreign Relations Committee (SFRC) - SFRC conducts hearings (S. Hrg) and makes recommendation to full Senate (S. Ex. Rept) - Senate passes resolution of "advice and consent" to ratification of the treaty (Constitution requires 2/3 vote of a quorum of the Senate) - President ratifies treaty.
For many countries, ratification procedures are summarized in Constitutions of the Countries of the World (linked from the Law Library's Research Resources page). Sources of State Practice in International Law (Basement KZ64 .S67) details the treaty ratification process for selected countries.