Guten Morgen. (= Good morning.)
Guten Tag. (= Good day. It is used roughly between 11 a.m. and 5 p.m.)
Guten Abend. (= Good evening.)
Moin. (= This is used in the north of Germany for the whole day.)
Grüß Gott. (= This is used in the south of Germany and some areas of Austria for the whole day.)
Grüezi. (= This is used in Switerland.)
Servus. (= This is used in the south of Germany and in Austria for the whole day.)
Hallo. (= Hello.)