There are various considerations to take into account when choosing a programming language on projects.

First of all, there is the "level" of a programming language, determined by the proximity of the language to the hardware. Low level languages correspond closely with the hardware, and high level languages offer a higher degree of abstraction.

Generally, high level languages give better portability. However, low level languages are more powerful because they are written to take advantage of specifities of hardware.
The choice of programming language for a project will depend on the nature of programming to be done. For example, to program a driver for an operating system, you choose a low level language, but for a complete application a high level language is more appropriate.

An example of a low level language is machine language. The instructions vary depending on the processor. Java is an example of a high level language; it is completely independent from the platform. The C++ language is placed somewhere between the two, as it can interact directly with the hardware layers and also function as a powerful high level language.