Tannins, in red wine, comes from the stems, seeds, grape skins and from the oak barrels they age in . White vino has very little tannin content because they have little contact with the stems, seeds and grape skins. The absolute majority of tannins in white wine comes from the oak barrels they age in. If, for a short time, you do allow it to remain in contact with their grape skins, it will be called a blush.
Tannins are important for reds, because it allows them to age . In a young wine that has not aged, the large content makes the wine taste sour and/or overly dry. As the red wine grows old however, the content decreases and forms as deposit in the bottom of the barrel.
They also give the reds its taste. If it is called firm, it has a large tannin content. If it is called soft, the content is low. But how many tannins in your glass of vino depends on the the drinker. Some like their glass of vino to have a high tannin content, while others like theirs with a low content, which they remove with a wine aerator.
The wine maker controls the amount of tannins he can produce by controlling the amount of contact the juice has with the grape skins, seeds and stems. But the drinker can also reduce tannins in their red wine, making it softer and giveing out more of the wines flavor, by aerating it or letting it breath.
Tannins are needed for red wines to allow them to age properly and to give them their distinct taste, either firm or soft.
To get rid of red wine tannins just before you pour the wine will bring out more of the wines flavor. To effectively remove the tannins, what you need is a wine aerator.