Technically that's gel electrophoresis. It's basically a way to sort molecules, mainly nucleic molecules like DNA and RNA. It's a relatively quick and easy way to measure length of chains. The thing on the left is basically a ruler, each stripe corresponds to a different length chain of DNA. The farther away it is from the top, the smaller it is.

Pcr is polymerase chain reaction, which is how nucleic acids are duplicated in bulk in a lab.

You mainly use it to compare stuff like genes and ribosomal rna. Genes don't change too much between strains, and ribosomal RNA is highly conserved (aka barely changes) between species. Basically you have your ruler, some controls +- and then your test sample/s. If your test band lines up with your control band, it's a match. Or its contaminated.

The smeary lanes on the left indicate something might be wrong with the gel or the voltage.