HTTP stands for Hypertext Transfer Protocol, communicated between servers and clients. It's a request and response cycle that involves headers and bodies.

HTTP is stateless-- each request is independent. It doesn't remember any of the previous transactions between those clients/servers. Local storage/cookies/session data is used to circumvent this.

HTTPS means everything sent is encrypted by SSL.

Status Codes are most useful to learn in General.

100 - In progress

200 - Success

300 - Further action needed

400 - Client Error (server needs a name field, for instance, and you don't send it)

500 - Server failed a valid request

Common Status Codes

200 : OK

201 : OK, something new was just made

301 : "This has moved to a new URL"

304 : Not modified? Unclear

400 : Bad request

401 : You don't have your token/secret

500 : could mean anything on the server side