Ok, I'm trying to wrap my hands around communicating over WiFi using a microcontroller. There seem to be various options such as UART, SPI etc.
If I want an Arduino to get or put content on a website, what protocol does the Arduino use to talk with the WiFi module? I see there are cheap UART WiFi modules available, but I don't think they have the TCP/IP stack built in.
How do I interface between a microprocessor and the WiFi module? Or what connections do I use? I2C, SPI, UART?
What are the minimum requirements for a WiFi module to be able to talk to a website? I want to read data from a website and write data to a website.
I hope this makes some sense, but to me it is still confusing.