Here's what I think I know.  Some of it could be wrong history.

Dbase became widely known during the Heydey of CP/M.  It was based on an
earlier product called "Vulcan".

It was a single user, desktop oriented database tool.  As such, it was
dismissed as a mere toy by people building massive systems around the twin
concepts of on line transaction processing,  and information integragion and
sharing.  Sad to say,  I was one of the people who dismissed it, for a
while.

It's interface language was considerably more primitive than SQL.
Nevertheless,  it did make storing and using m:n relationships feasable at
the desktop level,  and you could use it to prepare reports.  Those two
capabilities were enough to guarantee its survival.

Within a few years,  "IBM Compatible"  became the de facto standard for
desktop systems,  MS-DOS became the de facto standard for desktop operating
systems,  and SQL became the de facto standard for database interface.  For
a while,  everybody in the Desktop world had heard of Dbase.  It was almost
a de facto standard of its own.  Then other entrants like Clipper or Paradox
grew up to compete in the same arena.

De facto standards never gain universal acceptance,  and there have been
passionate and articulate opponents of all three of the standards I
mentioned above.  But de facto standards have a source of strength that de
jure standards usually do not:  a lot of people accept them merely because a
lot of other people have already accepted them.

I do not know the history of how SQL was grafted onto Dbase.  But even
without knowing the history,  I'm pretty sure it was a graft.

I know nothing about MySQL other than the name.

The name itself suggests to me the ultimate in desktop fantasies:  "I am a
rock; I am an island.  I touch no one, and no one touches me."  That fantasy
contains the seeds of its own doom.  The minute a desktop developer shows
his work to three other people,  and two of them say,  "Hey that's great!
Can I use it, too?"  the rest of the trajectory is certain, for those of us
who have learned from history.

Thanks you for fast reponses to my question.

Well now that I know what is the different between dbaseIV and MySQL,
I want to dig deeper. Deeper in a sense that I am a novice as far as
dbase concern. Actaully I don't even know how to use dbase.

Anyway the concerns I have so far are

1) I tried importing some dbf files into ms access. However I notice
that value of primary key field is not showing in access tables. The
reason I can tell is that I use Excel to open up the dbase table and I
can see those values. However after importing into access, those
values become invisible. I say "become invisible" because I can still
sort the field but I just can't see the values. For some reason those
values become invisible. Any idea?

2) How dbase table is organized?
I know how MySQL and Access are organized. However, since dbase is not
set-oriented, therefore I would like ask "how table in dbase is
related to each other?"

Again. Million thanks to those who response. THANK YOU!

Tony