Technical indicators compose a separate class of mathematical transformations, that allow to show those or these results. As a rule such primary indicators (from the point of view of technical analysis) is the price and the volume. However they are not the only "original sources". It also should be listed volatility, for example, or correlation with other financial instruments. We will talk about the price firstly to make the description more clear for the beginning traders.
There are some hundreds of more or less well-known indicators and thousands of different variations and authors' developments of different traders, that are less wide-spread, but are used in trading in some cases. We have no such a possibility to list all of them, that is why we will note two major classes of indicators: trend indicators (or trend-followers) and advanced (oscillators). Now we will review two examples for each indicator class.