The Native Navision Database is the original database (AKA FDB-files - for Financials DataBase). The base format has followed Navision since the release of the DOS based Navision 3.00 in 1989.
Using the Classic Navision Client it's possible to rune the FDB file directly in single-user mode. But it's also possible to run in a multi user server based mode using the Native Navision Database Server.
The Native Navision database is know for it's very solid design, where technical errors and damaged database files is an almost exceptional situation. The database was created by Navision co-founder Torben Wind.