This is a very common cloud and actually the same cloud as a stratocumulus but at higher altitude. The brand of this cloud is its pattern, clearly visible on this picture, and normally covers all or almost all of the sky. Although this example is quite thin and lets the blue sky through, it sometimes is thicker and shows a white or grey layer. Don't mix this cloud with an altostratus, which doesn't have the typical pattern.

Again the patterned layer of an altocumulus. Here in the sunset giving a beautiful pinkish colour.

The pattern can sometimes look like 'streets' in the sky.

Another very clear altocumulus pattern.

And another...

Flying above an altocumulus layer it can look like this. The pattern is clearly visible even from above, here at sunset.

Again the pattern clearly visible from above.

The sky seen here is commonly seen and shows how an altocumulus layer can cover most of the sky, whereas some parts are empty and blue. The typical altocumulus pattern is not very clear even though a pattern of direction towards the horizon is seen.

An altocumulus layer doesn't have to be evenly spread across the sky. This example shows how holes in the layer can give exciting formations.

Some remains of an altocumulus layer in the sunset.

The typical pattern, but not quite covering the whole sky.