Definition - What does Product Release mean?
Techopedia explains Product Release
The product release is part PR and marketing. A good release will create buzz and create demand of the actual product before its formal launch. That being said, a release is still important from a technical perspective -- when done well, a product release can get valuable feedback from the power users. This buys time to make improvements, fix bugs, etc. prior to release to the general public.
Note that in some contexts a product release refers to the date where the public can buy a product. In software development, there are usually releases prior to the final product. For example, for a major product from Microsoft, you'll often see "release candidate 1," "release candidate 2," etc.