The short answer is, your monitor and the internal display of the MacBook at two different resolutions and probably even aspect ratios.
Generally what you want to do, if you're not planning to use the internal display as well, is just close the clamshell after you power the unit on.
Hello all,
<div> I usually just scout the forum when I need some help and can
find a previous post that answers my question. I, myself don't have much
computer advice to offer, so I have never registered here. However, I can't
seem to find out whats going on between my MBP and this Samsung P2250 monitor
that I got recently. I cant get it to display at full capacity. I have read
multiple articles/posts regarding this topic with no luck. I apologize if this
is lengthy but Im just trying to include all of the info I have.
</div>

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