Cloudflare has a network of servers around the globe to help their customers improve performance metrics and deliver content as quickly as possible. Cloudflare services sit between the requesting client and the content publisher's website, essentially acting as a reverse proxy. Cloudflare cache servers deliver content as close to the requesting client as possible in order to speed up delivery times.
Cloudflare has both free and paid Cloudflare Pro offerings. Free offerings include basic distributed denial of service (DDoS) protection, but no image optimization. The full-featured version accelerates image delivery and offers firewall protection to help eliminate undesired traffic.
CloudFlare has a market share of over 35%. IDC Marketscape ranked Cloudflare as a leader in DDoS prevention in 2019. The CDN has numerous high-profile customers including IBM, Zendesk, Reuters, Udacity, the Library of Congress, Discord, Marketo and Digital Ocean. Cloudflare is backed by QUALCOMM, Microsoft, Baidu and Google.
This video from Newbird Academy proves an overview of Cloudflare services.