Why Java is used extensively in todays applications what makes it different from other languages?

Java is focused purely on applications programming; it is not a general purpose language. It shares a common syntax with C++, but is much easier to learn and use and has little in the way of low-level interaction with hardware; it is extremely high-level. Although a compiled language, the source code compiles to a machine-independent byte code rather than a machine-dependent code. This byte code can be executed upon any machine with a suitable Java virtual machine (which is pretty much everything these days), which acts as a runtime interpreter. Thus Java is both compiled and interpreted. Although the byte code is much slower to execute than native machine code and the implementation consumes far more memory than would otherwise be required, the simplified cross-platform ability alone makes it highly popular with applications programmers.