Column 1 : Alkali metals
Column 2 : Alkali earth metals
(that big ol 9 columns) : Transition metals
Column 7 : Halogens
Last column : Noble gases
First row : Lanthanides
Second row : Actinides
A group : same elements in a column, elements in the same group has the same amount of valence electrons.
A period : same elements in a row, elements in the same period has the same amount of electron shells.