The FMdatabase object will initialise and get some relevant info from the database, like fieldnames, layoutnames etc. This might take a couple of seconds. After initialising the FMdatabase object can be used like a list of record objects. The FMdatabase object itself also can perform finds, run scripts, delete and create records, count records, and provide access to the data in records through a record object, the FMrecord. The FMrecord object behaves more or less as a dictionary.
Keys are the fieldnames, values are whatever the cell's value is.
For each lookup the FMrecord object sends appleevents to Filemaker to access the data. It returns a regular dictionary with all the fields and values. Obviously changing values in this dict won't affect the database. Values are return in the field type they have in Filemaker. Strings will be strings, numbers will be numbers.