Bosniaks and Slavic Muslims separately? What is the difference? Biosniaks are Slavic Muslims.
Bosniaks are either ethnic Serbs or ethnic Croats, and some can trace their roots back to the Ottomans (i.e. they're Turkish).
This is the only case where the state is older than the people. All nation-states got their name from the founding ethnic group. i.e. Franks --> France; Serbs --> Serbia; Germans --> Germany; but Bosnia --> Bosniak.