1. A map updating system comprising: a memory configured to store map information, including one or more pieces of difference update information; a controller configured to: obtain the one or more pieces of difference update information, each piece of the difference update information being configured to update only a specific area of the map information stored in the memory; perform a difference update on the map information based on the one or more pieces of difference update information; record to the memory the difference update information that were used in the difference update; obtain total update information, the total update information being configured to update a total area of the map information stored in the memory; perform a total update on the map information based on the total update information; compare, after a total update is performed, a version of the total update information used in the total update with each of versions of the one or more pieces of difference update information that were recorded to the memory before the total update; extract, from the memory, any of the one or more pieces of difference update information of which the version is judged to be newer than the version of the total update information; and update the map information on which the total update has been performed based on the any of the difference update information.