The most common example of End Grain is a cutting board or butcher block. Pieces are glued together with the cut end facing up, usually in a checkerboard pattern. End grain is used for a reason! Think about a bundle of straws, but imagine the straws microscopically thin and hard. Now imagine someone splitting logs for a fireplace. We bring the axe down where we can see the rings and the wood splits. This is splitting the straws into bundled sections, its easier to push the straws apart, instead of cutting them into smaller straws. This applies to your knife as well. As you cut through your vegetables on an endgrain cutting board, the thin knife edge finds its way in between the bundled straws and slightly pushes them apart. This is great, because it keeps your knife sharper over time and it also produces much fewer scratches on your beautiful cutting board.
A Long Grain or Face Grain cutting board scratches easily. The image on the bottom left is a blown up version of a Face Grain cutting board. The knife comes down across the grain structure of the wood. You could cut with the tubes, but ultimately, the structure between the tubes will be separated, and pieces of the board may splinter out. The knives will ultimately scratch and damage the tubular structure and it will dull your knife faster. Long grain cutting boards are usually more attractive and are better suited as serving trays.
Just a reminder, keep you wood cutting boards out of the dishwasher. If they are looking dry and worn out, you can coat them in mineral oil or walnut oil. Cover them with as much oil as the board will soak in, then wipe of excess. Do this a few times a year. Olive oil and others may spoil over time and shouldn't be used as a treatment.