The simplest computer program

Years ago , (in the 70s I think ) I tried unsuccessfully to understand how you could write computer code. I got as far as binary numbers but no further .

Apparently a string of zeros and 1's could be read as a command to a computer.

So is any one able to give me the very simplest example of a command .I guess there also has to be a rudimentary language to "translate" this series of binary digits?

So say all I wanted to do was to write the very simplest command conceivable what would be the shortest series of digits and what could be the most rudimentary "language" ?