Robots and computers both use the same language, since a robot is really just a computer that can move. Computers all speak binary. Binary has only 1's and 0's. For example, the letter 'A' is represented by 01000001. Computers store all this information in memory. Numbers are represented the same way, so '6' is 110.
It takes special software, also written in binary to interpret the code and make the computer do useful work. Programmers rarely write in binary, since it would be too tedious and you would probably make lots of mistakes, so they use other languages, like C, PHP, Basic, Cobol, etc., that make it easier by using more English sounding words and translating them to binary. Here is an example written in PHP
for($i=1;$i<=10;$i++) echo $i;
This will output the numbers from 1 to 10. It all gets translated to binary first and then the computer can perform the action. The binary code can only do very simple things, like move binary 1's and 0' right or left, add them, move them to another location in memory, etc. However, you can combine these very simple operations to create anything.
There is a lot more to it, but hopefully this gives you a general idea.