Bytecode is a generic word for the instructions executed by a virtual machine, in the same way that machine language is a generic term for the instructions executed by a real processor. Just as there are many different machine instruction sets, there are many different bytecode instruction sets. Some, like Java bytecode, are a documented part of a platform. All Java virtual machines execute exactly the same bytecode, by definition. Others are just an implementation detail, and differ from version to version.
To answer your last question: no, that is not correct. Java is not an interpreted language; it is just-in-time compiled. C# is similar. Bytecode can be a part of many different architectures.
Answer from Ernest Friedman-Hill on Stack Overflowjvm - Bytecode differences in different programming languages - Stack Overflow
pypy - Is Python byte-code, interpreter independent? - Stack Overflow
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Bytecode is a generic word for the instructions executed by a virtual machine, in the same way that machine language is a generic term for the instructions executed by a real processor. Just as there are many different machine instruction sets, there are many different bytecode instruction sets. Some, like Java bytecode, are a documented part of a platform. All Java virtual machines execute exactly the same bytecode, by definition. Others are just an implementation detail, and differ from version to version.
To answer your last question: no, that is not correct. Java is not an interpreted language; it is just-in-time compiled. C# is similar. Bytecode can be a part of many different architectures.
As Ernest mentioned it is vendor dependent bytecode implementation from different languages. While there are already attempts to standardize bytecode. Have alook at solution from Microsoft CIL
Worth to mention LLVM compiler which becoming glue for different bytecodes providing optimizing compilation to any CPU instruction set.