What is SAP hybris?
https://www.quora.com/What-is-SAP-hybris
On one level, it is an eCommerce suite of highly integrated products for selling principally online, geared towards higher end markets.
These include tools to design your web site using pages and components, a product information management tool, a customer service tool, back office management tools, enterprise search tooling, marketing related functionality, and lots more.
This standard tooling is available from a number of sample web sites called storefronts based on Spring MVC applications called accelerators, which help reduce a lot of the graft from a project. There are examples for B2C, B2B, China, Financial Services, Telco and others are emerging too. The gap between these closes between releases too, so we see functionality from one accelerator such as B2B start to become available in other accelerators too, which is great because the lines between these become more and more blurry as the eCommerce marketplace evolves
This is built with extensibility in mind using a rich set of patterns-based tooling that any Java developer can quickly understand, although the sheer quantity of functionality can be somewhat daunting.
On another level, hybris is a brand within SAP encompassing a related product line, mostly relating to marketing tools and a microservice platform, so be careful if you are looking at something that isn't called the commerce suite - it may not have the same customization characteristics that you are expecting.
And of course, hybris is the name of the company that SAP acquired some years ago, the brand value being acknowledged as strong enough to not only survive, but be adopted strategically in related products even now.