Which machine language your computer supports depends on the type of CPU installed on it. Intel CPUs understand one language, Motorola CPUs use another, and so on. The language used by different CPUs from the same manufacturer is often similar, although not exactly the same. For example, programs written for Intel's 486 CPU will run on a Pentium CPU, but not all Pentium programs will run on a 486. Although it's possible to write programs in machine language, that's not what programmers typically do.
Machine language is extremely primitive, making it difficult to write even simple programs.
Instead, most programmers use high-level languages that aren't tied to any particular computer. C - Developed by Bell Labs in the 1970s in conjunction with the UNIX operating sytem, C is often used for programs that need to be very fast or run in a limited amount of memory. But Java's significance goes beyond Web applets, and full-scale sophisticated applications can be written using Java. Pascal - Designed in the early 1970s, Pascal became the leading language for teaching computer science during the 1980s. Source code is not executable - there is no direct way for a computer to follow the commands that it contains.