Candle sticks are very popular ways to view the movement of stocks as it provides 4x more information than a basic line graph.
In this post I am not going to overload you history and all sorts of technical analysis related matters as in my opinion it's best to keep things simple.
Here is a real life example of a candle stick chart:
So how do we read that?
The most obvious feature that stands out is the colours. Each candle has a colour, which tells us whether the price moved up or down during the given timeframe. It doesn't matter what the colour combinations are as long as you know which colour means down/up movement. However, if the candle 'body' is only represented by a line (see below) then there is no need for 2 colours.
The longer the 'body' of the candle is, the bigger the price movement was during the given timeframe.
The width of the candle means nothing. Sometimes the 'body' of the candle is only indicated by a line (see below).
The side boundaries don't matter at all but the top and bottom are critical. The top part of the candle 'body' can represent either the open or the close price depending on the colour. On the above example, the red candle shows a downwards movement so the top part of the body shows the open price (the price at the time when the market opened). The bottom shows the close price. However, the green candles are the opposite.
The sticks show us the high/low of the day. Sometimes there is no sticks at all. Longer sticks mean larger price movement during the given timeframe. For example, if there is a candle where there is a very long stick pointing downwards then it means that during the given timeframe the price of the underlying (e.g. stock) dropped a fair bit but then managed to bounce back.
This attribute is not specific to the candle stick charts but it's important to note what timeframe a given candle represents. It might be 1 second or it could be a whole year. You select the timeframe based on your objectives. For example, you may want to view the 15 minute movement of a stock as you want to understand the action during the day. Other times, you may want to view a monthly chart so that you can get a better perspective of the current price compared to a long-time history.