Bytecode can be described as a compilation of program code into low-level code from source code that is designed for a software interpreter. The execution of bytecode can be carried out by a virtual machine, such as a JVM, or rather, being compiled into machine code, and which the processor recognized.
The different syntax is made use of by different types of bytecode, which can definitely be executed after being read by a virtual machine. A famous example is the Java bytecode, which can be run by a Java Virtual Machine (JVM) after being compiled from java source code.
As a matter of fact, you can write bytecode directly if you are a programmer, but you will agree with me that it is more difficult compared to writing code in such a high-level language like java. Therefore, it is recommended to make use of a compiler like “javac” to generate bytecode files from source code.