AMP stands for “Accelerated Mobile Pages.” It is an Open Source Framework that was launched as a joint initiative by Google and several other technology and publishing companies. With AMP, it is possible to create simple mobile websites that load almost instantly.
AMP is definitely helpful for SEO as speed is a significant ranking factor and AMP can improve server performance (if your site generates lots of traffic from mobile, AMP will reduce the load on your servers). But if you have a fast site already, it might not be hugely worth it. You have to keep updating AMP code, AMP is experimental and can break frequently. At a recent conference I saw an example of a whole page break just because it had a broken link in it. Building AMP pages is hard, typical engineering time involves 2–3 months for a ~5K page website. Also AMP analytics is quite basic