Learn English – Difference between “composite” and “compound”

Yes. Continuous means from some start to some end without break:

The water flowed continuously over the dam.

whereas continual means occurring repeatedly at intervals over a time span:

I continually lose at poker.

I should also mention that continual is often substituted for continuous, and would be correct in most contexts, however the converse is not generally true. That is to say,

The water flowed continually over the dam.

is okay, but you would (hopefully) not mean

I continuously lose at poker.

since that would imply that all you do all day long is play poker and lose.

Clearance is most often used (but not exclusively) when a shop wants to clear a particular stock line. In your example this would be CookiesKids. The reasons vary, but most often because they're not stocking that line any more or they simply want to clear old remaining stock before the new season stock arrives.

Sale is most often used when referring to multiple branded stock items or more than one type of item from the same brand. In your example this applies to multiple brands or items from the shop or brand Woodwind & Brasswind.