Derived from arabic roots meaning 'peace' and 'submission to God'. Those who follow islam and submit to God (known on arabic as Allah) are known as muslims
(note the small 'm').
Someone who calls themselves a Muslim (big 'M') may or may not follow Islam in the same way that someone who calls themselves a Christian
may or maynot follow the teachings of Christ.
Followers of islam take their guidance from the Qu'ran
which is believed to be the word of God and also from hadith - which are trusted stories about the guidance that one of the prophets (Muhammed) gave.
This is like Christians taking guidance from the gospels - stories about what Jesus
(another prophet in Islam) taught.
You cannot be a muslim if you don't believe in all the prophets God sent including Adam, Noah, Abraham, Moses, Jesus, Mohammad and many others (25 are named in the Quran but we are told there were thousends).
Muslims have lived peacefully in the UK for centuries. An 8th century anglo-saxon kings produced coins in the declaring in arabic 'there is none worthy of worship but God' (the islamic declararion of faith). The first English translation of the Qu'ran was written in 1649 and the office of national statistics records a Mosque in cardiff in 1860.
is something relating to Islam.
is a made up word that muslims never use. It implies a radical form of behaviour that deviates from the teachings of Islam and is used when the media and politicians want to say islamic-terrorist and think that us mere mortals will be fooled by their clever twist of language.