How does the PC understand that now it needs to read 8 bits for a character, and then 16 for another?

Question

binary code

How does the PC understand that now it needs to read 8 bits for a character, and then 16 for another?

Answer 1

I answer myself:
If you need 2 bytes, then 2 bytes are used. The encoding tells the most significant bits how many bits encode the current character. This method saves space, but also wastes it if these signal bits are used frequently.