What exactly “creating the software themselves” means? Does it mean to write binary code? To write assembler? To write software in C? To write software in Golan

What exactly “creating the software themselves” means? Does it mean to write binary code? To write assembler? To write software in C? To write software in Golang? To write software in prompts? If any the demo just showed me the next high level programming language: pseudocode (or just plain English)