High level code and machine code

What is machine code?

What are the instructions - opcodes and operands - represented by?

Does every processor type have its own unique instruction set?

Is it difficult for humans to learn strings of bits?

Is writing, testing and debugging fast or slow?

What is used in assembly language to represent opcodes?

Why is assembly language called a low-level language?

What are high-level languages similar to?

Why are high-level languages better to use?

Why are translators used?

What does an assembler do?

What are the two ways of translating high-level languages into machine code?