a basic question

[M.P.N. Peters]

L.S.,   Recently I found out about Unicode and UTF-8. Unfortunately, it raises a lot of questions. My first question is, how can I, with a limited (= qwerty) keyboard that can generate only about 100 scancodes (I think), produce all the keycodes needed to reach for example the phonetic characters? In other words, I think the question is how a single scancode can have multiple keycodes? Thanks in advance,   Mark