Ars Technica has an article about it, also confirmed by the search liaison Twitter account.

Not sure if this qualifies as it's only a feature, but it was a large and useful one.

What's the Product's Name?

Google Search Cached Pages

Describe the product in a single sentence.

Google Search Cached Pages allowed users to view archived versions of webpages stored by Google Search.

When was the product launched? Provide a specific date, if possible.

The earliest I could confirm was as early as Dec 2000 from this archived search page which shows Cached links directly in search results

Im not sure I can confirm any earlier date than Dec 2000. I can't find any images of search results before this date and didn't look harder on archive.org.

Google search started in 1995? So sometimes between then and 2000.

When was the product discontinued? Provide a specific date, if possible.

No date except "near future" after Feb 2024. The cached link from the sidebar was removed, and the cache: has yet to be removed but is confirmed to be removed in the future.

What type of product was it? App, Service, or Hardware?

Service or App. It's more of a feature