How to set font in Beamer

If you are not satisfied with the font themes that ship with Beamer, you can use any font family you want for your Beamer document. The font family you intend to use has to be available as a package. For example, to use the Helvetica font family include:

\usepackage{helvet}

The font theme has to match the style of the font family, else the resulting document may have a mix of fonts used in it. That is, use the serif font theme for a serif font family and so on. For example, to use the Concrete Math font family (which is serif):

\usefonttheme{serif}     % Font theme: serif
\usepackage{ccfonts}     % Font family: Concrete Math
\usepackage[T1]{fontenc} % Font encoding: T1

Sometimes, a font encoding may also have to be specified for the font family. For example, the T1 font encoding for Concrete Math font family in the example above.