ESP32: Sketch uses 310749 bytes (23%) of program storage space. Maximum is 1310720 bytes. Global variables use 15388 bytes (4%) of dynamic memory, leaving 312292 bytes for local variables. Maximum is ...

It is very detailed! This information is also summarised every time you compile a sketch using the Arduino IDE. The program storage space is Flash memory, and the dynamic memory is referring to SRAM.

When [sticilface] started using the Arduino IDE to program an ESP8266 ... you’d like to store data that won’t change in program storage instead of RAM. They still eat up memory, of course ...

While the ability Arduino now can communicate with each other through serial communication. On the other side the need for communicating security is required. But the computing capabilities and ...