Pseudopodia are temporary, foot-like extensions of a cell's cytoplasm. They are primarily found in certain types of cells, such as those in the Amoeba genus, and are used for movement and feeding. By extending and retracting these projections, the cell can crawl along surfaces or engulf food particles. These structures play a crucial role in the process of phagocytosis, where a cell surrounds and takes in large particles or other cells. Pseudopodia are also important in the immune response, as some immune cells use them to capture and destroy pathogens.