Answer:
Longitudinal and central plan churches are two different types of church designs that emerged in the history of architecture, each with its own unique characteristics and features.
Longitudinal churches, also known as basilica-plan churches, are characterized by a long central nave that runs the length of the building, with aisles on either side and a semi-circular apse at the end. These churches typically have a defined entrance, and the focus of the interior is on the altar at the end of the nave. Examples of longitudinal churches include the early Christian Basilica of St. Peter in Rome, and the Gothic Notre-Dame Cathedral in Paris.
Central plan churches, on the other hand, are characterized by a circular or polygonal design, with no clear division between the nave and the sanctuary. These churches often have a dome or a central tower as the main structural feature, and the focus of the interior is on the central area, rather than on a specific altar at the end. Examples of central plan churches include the Byzantine Hagia Sophia in Istanbul and the Renaissance Church of Santa Maria degli Angeli in Florence.
In summary, the difference between longitudinal and central plan churches lies in their basic architectural design and the focus of the interior. Longitudinal churches have a defined nave and altar, while central plan churches have a central area as the main focus.