Who can explain the differences

I've read many posts about how great Maris Otter malt is. My LHBS only carries Hugh Baird. Can anyone explain the differences?

The difference is quite simple: Maris Otter is a type of barley, Hugh Baird is a brand.

Maris Otter is a two-row winter barley and works well in any English beer style. It's available from several different maltsters.

Hugh Baird & Sons is one such maltster; they produce malt from two-row UK barley at facilities in Pencaitland, Scotland and Witham, England. One of the malt varieties that they offer is Maris Otter Pale Ale Malt.

I'm far from an expert but I think Hugh Baird actually produces Maris Otter along with other malted barley products. Take a look at this site.
http://www.northcountrymalt.com/pages.php?pageid=12

EDIT: flowerysong's answer was muuch better than mine!

Yep Hugh Baird makes a maris otter. Maris Otter is a specific type of base malt and hugh baird is a brand. You may actually be getting hugh baird maris otter.