This chapter defines the concept of an easement and outlines its establishment rules, emphasizing that it is created upon the effectiveness of an easement contract and gains opposability against a bona fide third party through registration. It highlights the diverse practical applications of easements, such as for passage, drainage, or restricting land use for purposes like preserving a view or preventing business competition. The text further explains key classifications of easements, including the distinction between agreed and statutory easements, positive (requiring tolerance) and negative (requiring omission) easements, which carry significant implications for their legal adjustment and methods of acquisition.