There are various ways to smoke cannabis. You can smoke a joint, rolled with marijuana or hashish mixed with tobacco, or with marijuana only. You can also smoke marijuana or hashish neat in a small pipe fitted with a screen. Or you can use a water pipe.
It is also possible to use a vaporizer. This heats the cannabis without burning it. In this way no tar or carbonmonoxide is produced. This method is a lot less harmfull for your lungs.