As an act of protest, occupation is a strategy often used by social movements and other forms of collective social action in order to squat and hold public and symbolic spaces, buildings, critical infrastructure such as entrances to train stations, shopping centers, university buildings, squares, and parks. Opposed to a military occupation which attempts to subdue a conquered country, a protest occupation is a means to resist the status quo and advocate a change in public policy. Occupation attempts to use space as an instrument in order to achieve political and economic change, and to construct counter-spaces in which protesters express their desire to participate in the production and re-imagination of urban space. Often, this is connected to the right to the city, which is the right to inhabit and be in the city as well as to redefine the city in ways that challenge the demands of capitalist accumulation. That is to make public spaces more valuable to the citizens in contrast to favoring the interests of corporate and financial capital.

Squatting is the action of occupying an abandoned or unoccupied area of land or a building, usually residential, that the squatter does not own, rent or otherwise have lawful permission to use. The United Nations estimated in 2003 that there were one billion slum residents and squatters globally. Squatting occurs worldwide and tends to occur when people find empty buildings or land to occupy for housing. It has a long history, broken down by country below.