By this definition a telephone book is a database since it stores information in a structural way.

Okay to correct myself earlier yes Access is a database, however, it doesn't compare on any level to more sophisticated databases, this is based on my experiences, I have used dozens of database systems everything from GDBM, to BerkleyDB, from Mysql to Postgres, from MSsql Server to Sybase and Oracle. Access has a pathetic method of locking (in the versions that support locking) so whilst it may support concurrent connections it may not be protecting the data. Database repairs often cause even more problems.

Also I wouldn't define myself as a MS basher admittedly I prefer unix like systems I also believe MS has a place and they fill that place very well, I do, however, have a particular dislike of Access this is based on my bad experiences with it, not on my personal feelings towards microsoft, if you want a database to store your personal records or your cd collection Access fills that space well, if you plan on having more than one person accessing it at a time then Access seriously lacks in certain important errors.