You can use graphics such as PNG or PDF files in your LaTeX document. You need an additional package, which comes standard with LaTeX. This example is the short how-to.
\include{graphicx} % goes in the preamble
...
\includegraphics[width=0.5\linewidth]{plot.pdf}
To use the commands described here your document preamble must contain
either \usepackage{graphicx} or
\usepackage{graphics}. Most of the time, graphicx is the
better choice.
Graphics come in two main types, raster and vector. LaTeX can use both. In raster graphics the file contains an entry for each location in an array, describing what color it is. An example is a photograph in JPG format. In vector graphics, the file contains a list of instructions such as ‘draw a circle with this radius and that center’. An example is a line drawing produced by the Asymptote program, in PDF format. Generally vector graphics are more useful because you can rescale their size without pixelation or other problems, and because they often have a smaller size.
There are systems particularly well-suited to make graphics for a
LaTeX document. For example, these allow you to use the same fonts
as in your document. LaTeX comes with a picture environment
(see picture) that has simple capabilities. Besides that, there are
other ways to include the graphic-making commands in the document. Two
such systems are the PSTricks and TikZ packages. There are also systems
external to LaTeX, that generate a graphic that you include using the
commands of this chapter. Two that use a programming language are
Asymptote and MetaPost. One that uses a graphical interface is Xfig.
Full description of these systems is outside the scope of this document;
see their documentation on CTAN.