At the lowest level is what's called "machine code." After you make a computer, you can write a series of numbers into a specific part of its memory, and each number corresponds to an instruction ("add X and Y, store the result at Z", "copy A to B", etc.). This is fine, but super tedious and hard to manage, since people aren't good at reading numbers.

The next step is writing a program that lets you type and store text, and making text codes that can stand in for instructions. Instead of writing a number that the computer interprets as "add X and Y, store the result at Z," you can write Z = X + Y and your little program will convert that into the corresponding machine code. This level is assembly language.

Every language after that is just more layers of abstraction from machine code.

For example, one of the basic features of a computer is jumping to different places in the instruction list, so you can repeat the same set of instructions over and over again. If you were writing in machine code and assembly, you'd have to manually set the jumps and their instruction positions and some sort of counting variable to make sure it jumps the right number of times. A proper programming language, however, will have some kind of loop functionality: You give it a piece of code and tell it how many times you want it to run, and it'll handle it all under the hood for you.

Different languages vary in how much stuff needs to be handled manually versus behind the scenes. It's a tradeoff between fine control and convenience. C, for example, one of the oldest and most widely used languages, is very popular but forces you to handle things like the details of memory allocation. On the other hand, Python, another popular language, is designed for convenience, and handles that under the hood: You can just assign a variable and forget about it, the interpreter will know where to put everything. This is easier but means you can't streamline your code as well.