Jamstack is an architecture designed to make the web faster, more secure, and easier to scale. It builds on many of the tools and workflows which developers love, and which bring maximum productivity.
Lightning Fast Websites
The main benefit to Jamstack websites is performance. Lightning performance. This is all done by "building" the website and bundling all the assets and content together, thus creating a static website that doesn't need to send a database request when a user visits! Everything is there and ready, and whenever the content changes in the CMS of choice, a trigger is sent to re-build the website.
Highly Stable & Secure
As there is no CMS "attached" to the website, there is no room for concern surrounding back actors attempting to access the website maliciously. It's extremely stable and secure, and the chance of the website breaking is slim.
As there is no CMS attached to the website, there is no need for maintenance like there would be on a WordPress website with constant plugin and themes updates. The only real cost is for hosting and content!
Arguably the best thing about Jamstack is flexibility. Because your content is all stored in one place, with no reliance on a technology or medium, you can easily swap over to something else. For example, if you have a website that's built in NuxtJS but you fancy changing to NextJS, you'll just have to think about the development and make a simple API or GraphQL call to pull the content in and you're all sorted!