You can write C programs in practically any text editor or IDE. Using a text editor instead of an IDE is advised at the beginning so you can fully understand the compilation process and all the magic happening behind. In this course you can use any editor you prefer.
Some editor examples:
Some IDE examples:
Difference between editor and IDE is in their functionalities. IDEs provide more functionality compared to editors, such as code refactoring, building and compiling projects, and similar. In editors you will many times need to use tools from the command line.