The words "virtual machine" and "interpreter" are mostly interchangeable; they both refer to a mechanism to run a computer program not by compiling it to machine code, but to some intermediate "virtual" machine code which will then get run. The terminology is new, but the idea is older, "P-code" was the term we used to use before it fell out of favor.
Sun popularized the term "virtual machine" when marketing Java instead of using "interpreter" or "P-code", both for marketing reasons (VMware had just come on the scene and was making tech headlines), but also to get away from the perception of classic interpreters being slower than native code since Java had a JIT compiler. Just-in-time compilers that compiled to the host's machine code at runtime were well-known in research domains at the time, but were much less popular than the more dominant execution models of "AST interpreter" and "bytecode interpreter".
There might be some gatekeepers that suggest that "interpreter" means AST interpreter (not true for the Python interpreter, for instance), or VM always means JIT compiled (not true for Ruby, which calls its bytecode-based MRI "RubyVM" in a few places), but you can ignore them.
Sun popularized the term "virtual machine" when marketing Java instead of using "interpreter" or "P-code", both for marketing reasons (VMware had just come on the scene and was making tech headlines), but also to get away from the perception of classic interpreters being slower than native code since Java had a JIT compiler. Just-in-time compilers that compiled to the host's machine code at runtime were well-known in research domains at the time, but were much less popular than the more dominant execution models of "AST interpreter" and "bytecode interpreter".
There might be some gatekeepers that suggest that "interpreter" means AST interpreter (not true for the Python interpreter, for instance), or VM always means JIT compiled (not true for Ruby, which calls its bytecode-based MRI "RubyVM" in a few places), but you can ignore them.