HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Kakao platform provides various services such as Kakao Talk, Kakao Talk Channel, Kakao Story as well as Kakao Pay, Kakao Commerce, Kakao Page provided by the subsidiaries. Users can use all Kakao platform services with a united account called Kakao Account.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Vercel is a cloud platform for static frontends and serverless functions.