Groups of people which have acquired international recognition as an independent country and which have a population, a common language and a defined and distinct territory.
„Entities that have a defined territory and a permanent population, that are under the control of their own government, and that engage in, or have the capacity to engage in, formal relations with other such entities.“
„Nationhood is a demographic and psychological phenomenon; statehood is a formal-legal phenomenon. Only states, that is, possessors of sovereignty, may become members of the state system.“
The 1933 Convention on the Rights and Duties of States (aka Montevideo Convention) specifically defines statehood, as:
„The state as a person of international law should possess the following qualifications: a permanent population; a defined territory; government; and capacity to enter into relations with the other states.“
Supreme authority within a territory — this is the general definition of sovereignty.
The ‘territories’ of an entity, whether Sovereign, state or stateless, titled or un-titled, belong to all the entity’s citizens, regardless of their political persuasions or ‘real estate’ ownership deeds. This includes the homeless, non-voting, non-land owning, alcoholic bum who lives under a bridge. This is true of all entities.
SOVEREIGN STATES: In order to become a Sovereign State, an entity must define and have full control over the territories it wishes to declare sovereignty over. The requirement to define is so that the International Community of States knows exactly what they are claiming as their own, in order to recognize them as a Sovereignty.Their Declaration of Sovereignty must then be recognized by the majority of the International Community of States. Recognition by the majority of the International Community of States overrides those states objecting.
Sovereign states can only acquire further territory by legal annexation. Ie., by agreement or treaty. Unilateral annexation is not permitted, nor is territory acquired by war or claiming armistice lines as borders when they weren’t borders before the armistice.
A Sovereign State acting outside the extent of it’s Sovereign borders, may only do so in accordance with International Law, the Laws of War, Humanitarian Law, (all mandatory, without exception) and if it is a UN Member, according to the UN Charter and any Conventions it has ratified (Contracting Power) and/or anything it has committed itself to uphold.
An Entity might/may exist independently or under the control or administration of another party or group of parties. This might/may be under agreement or occupation. Under an agreement, it becomes a protectorate or is under the UN Charter for Trustees. An entity under occupation is protected by the UN Charter Chapter XI. Any entity may undertake to adhere to International Law, the Laws of War, Humanitarian Law and/or the principles of the UN Charter.
In respect to the Geneva Conventions, if an entity is a protectorate or under a trusteeship or being represented (e.g., the Arab States represented Palestine), the protector or trustee/s are the High Contracting Power under which the Geneva Conventions apply. Prior to the Geneva Conventions coming into force, they were still bound by Customary International Law, the Laws of War and where applicable, the UN Charter.
A declaration of statehood is not made on behalf of an entity by a Government or a political party. Political parties & regimes change. It is made by a politically neutral body which only exists for the time it takes to declare statehood and institute a political system in the new state. As such, they might have a mandate. They do not have a charter.
An entity may declare statehood under occupation, it CANNOT declare sovereignty under occupation.
In order to be recognized, a declaration is made by a politically neutral body, on behalf of all the people within the territories  being claimed for the state, regardless of their political persuasions. The declaration is TO the International Community of States in order that the declaring entity be accepted as a part of the International Community of States, as a state.
Recognition is granted on the basis that the new state has defined boundaries and that it will adhere to International Law.
An entity – any person or identifiable group of persons.
State – Defined territory. (Could be assisted in controlling it’s territories. Not independent)
Sovereign state – In total control of the territories being declared. Independent.
Borders – All states are defined by borders/boundaries. Non-state territories are usually defined by default, by the defined boundaries of their neighbours. I.e., if it isn’t sovereign territory of Lebanon, Syria, Jordan, Egypt or Israel, it’s a part of the non-state entity of Palestine.