Decisions around what to call a conflict usually aren't so straightforward or logical.

There are often multiple names for the same conflict, and what it is called can depend on whether a person is a supporter, opponent, or outside observer. Additionally, sometimes people and groups will change what they call a conflict after it is finished and the result casts new perspective on it.

A few examples:

There was a conflict in South Asia in 1857-59 where Hindu and Muslim soldiers and rulers fought against British East India Company rule. In the British press and in British textbooks, the conflict was for a long time called "the Sepoy Mutiny". Recently, there has been a scholarly effort to instead call it The Rebellion of 1857, in recognition of political aims (mutiny = soldiers acting lawlessly. Rebellion = political aim to conflict). On the other hand, among Indian nationalists before 1947, it became common to call that conflict the First War of Indian Independence.

Or let's take the example of Zimbabwe. When South Rhodesia issued a Unilateral Declaration of Independence in 1964 to avoid a decolonization that granted voting rights to the black majority, there followed an insurgency by African nationalists demanding decolonization and majority rule.

The conflict from 1964-1979 was called the Bush War by the White minority-rule government of Rhodesia, to emphasize the small-scale rural rebellion aspect. Newspapers in the United States and Europe tended to call it the Rhodesian Bush War, and after the war white Rhodesian veterans wrote memoirs of the war, reinforcing that name in popular consciousness in the West. However, in Zimbabwe after 1980, under majority-rule nationalist government of Robert Mugabe and the Zambia African National Union - Popular Front party, the war from 1964-79 is called either the Zimbabwe War of Liberation or more popularly the Second Chimurenga. That name draws implicit comparison to the Second Matabele War or First Chimurenga, which gets cast as a first unsuccessful war for national liberation against British South Africa Company rule in the 1890s.

This also brings us to the issue of Colonialism. If there was an armed conflict that threatened the colonial administration, the imperial power never would legitimize it by calling it a civil war. Major conflicts like Egypt and Britains war in Sudan from 1889-1899 was called the Mahdist Revolt or the Sudan Campaign at the time (though more recently recognized as the Mahdist war).

Ditto, the major conflict in German East Africa from 1905-1907 was called the Maji-Maji Rebellion in German and British press.

In Kenya colony, settler and British press at the time called the period from 1952-1960 the Mau Mau revolt, or Mau Mau uprising.

Again, the careful use of language to portray anti-colonial violence as "rebellion" against the legitimate colonial order.

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With all that in mind, here is what I have observed as common usage of the terms rebellion, civil war, and revolution.

In the context of Colonial Africa and post-independence Africa, "rebellion" is often used to refer to short periods of protest or armed conflict, opposing specific policies. For instance, the Hut Tax War of 1898 in Sierra Leone was the Temne people resisting imposition a new tax on everyone's houses.

Similarly, the Bambatha Rebellion was an armed revolt in 1907 against Natal colony cutting down Zulu autonomy and imposing a new Poll tax to try and force Zulu peasants into migrant labor in the gold mines of Witwatersrand.

The Aba Women's revolt was protests at markets in Igboland in southeastern Nigeria in 1929. Women market traders were outraged at new taxes imposed on the markets, imposition of new warrant chiefs and new courts.

Or in the post-colonial era, the Agbeyoka revolt in 1968-69 in Southwestern Nigeria was again peasant protest against corrupt local officials and imposition of new taxes during the Nigerian Civil War.

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Generally speaking, conflicts are considered Civil Wars when there are two or more sides that have clearly established governments/administrative apparatus which each claim to be the legitimate government, along with established militaries/armed wings.

So for instance, in the Russian Civil War of 1917-1923 there was the Bolshevik government in Moscow, with an established Red Army. They were fighting against an assortment of opponents who either supported the Czars or the Nevsky government, organized into several loosely-affiliated White Armies. These White Armies had support and armed intervention from UK, France, US and Japan.

Or with the Chinese Civil War, there was an established Guomindang government headed by Chiang Kai-Shek with his National army, fighting against the Chinese Communist Party and the Peoples Liberation Army from 1945-49. Guomindang had recognition from US, UK, etc while the CCP had recognition from Soviet Union.

Or in Nigeria there was a war between Yakubu Gowon and the Nigerian Federal Government against secessionists in Biafra. Biafra had an army, and a government led by Emeka Ojukwu, and had lots of international recognition from European and African countries. And of course, Biafran nationalists called and call it the Biafran Independence war, not the Nigerian Civil War (which is common name)

So, yes, rebel movements that succeeded in Eritrea, or Yoweri Museveni in Uganda, or the CCP in China have all come to call their conflicts "war of independence" or "National Renaissance war" or "war of people's liberation". But from outsider perspective, those tend to get value-neutral monikers like Ugandan Civil War, or Chinese Civil War. Eritrea's war did result in secession from Ethiopia, so it is called Eritrean Independence War, or it is addressed as part of the Ethiopian Civil War which was happening at the same time.

TL:DR- it's confusing, and what a conflict is called depends on your point of view, and sometimes reflects retrospective judgments.