A late endosome is an essential membrane-bound organelle within the cell that functions in the endocytic pathway. It is a crucial intermediary stage between early endosomes and lysosomes. Late endosomes are involved in sorting and transporting cargo, such as proteins and lipids, from the plasma membrane to lysosomes for degradation. They are characterized by their acidic environment and the presence of specific markers such as Rab7 and Lamp1.