Protectorates.
The colonies.
The industrial boom.
Scientific interest.
Ideological justification.
Concessions.
The increase in population.
Domains.
The nationalistic spirit.
Regions where the colonial powers controlled foreign policy and the exploitation of the country's wealth, while the native elite was in charge of domestic policy. One example was Egypt, one of the main British protectorates.
Territories in which a large amount of European population was established with its own government. This system was used by the British Empire in nations such as Canada, Australia and New Zealand. The dominions enjoyed complete autonomy in domestic policy, but foreign policy was decided in the metropolises.
The process of industrialization led the European powers to seek new markets to obtain raw materials and sell their products in territories outside Europe. Even those who advocated European domination over other peoples argued that it was necessary to achieve the economic progress of their nations.
As you have already learned, improvements in medicine and hygiene, among other reasons, led to a growth in the European population. Soon, the lack of space, the scarcity of work and resources encouraged the migration of millions of people to other continents, with the aim of seeking wealth and improving living conditions.
Territories subject to the sovereignty of the metropolis and administered by it; for example, the Belgian Congo or British India.
Territories of an independent country, in which the Western powers obtained commercial advantages. One example is China, which was not conquered, but granted trade privileges to various powers.
Intellectual currents, such as social Darwinism, installed the idea that Western civilization was superior and that imperialist expansion had a civilizing and evangelizing mission that would bring progress to those nations that had not been able to access it.
For many scientists of the time, the importance of observation in the development of science required the recognition of all regions of the planet. This led to various geographical explorations that paved the way for the expansion of European states by hitherto unknown continents.
The ideology of nationalism and the recent unification of states like Germany and Italy, which you studied earlier, fostered the European imperialist desire to expand their domains and conquer new territories.