But what does that mean? Do they receive event data or timeseries and graph it?
they forward those events to all of your other systems (e.g. CRM, webhook, helpdesk). they can also do some data health/quality monitoring.
It seems that this open source library can directly submit web tracking data to multiple platforms, like Google Analytics. If this is the case I don't understand what Segment the company does.
I understand that I am probably not their target population, but I really can't decipher the buzzwords on their website.
No. There is no data visualizer inside of Segment. It’s a very expensive customer-data-infrastructure tool.
Integrate segment with your application on the web and mobile and you can enable or disable downstream data delivery to any one of the services at https://segment.com/catalog/ without touching your code. This leaves your engineering team free of requests to integrate your product with new services your marketing and analytics teams want to use.