Yes, that is a "slide tackle". A tackle in soccer is really any play where the defender tries to take the ball from the ball carrier.
examples: Block tackle
The block tackle is the most basic way of depleting an opponent of the ball. It is designed to give you possession while keeping you on your feet. Plant your supporting foot firmly so that you don't lose balance. Then, just as your opponent contacts the ball, you must put your free foot perpendicularly to the direction in which he is moving. If executed properly, this will cause your enemy to stumble or cough up the ball.
Poke tackle
With poke tackling, you basically stab the ball away from your opponent. You must use the foot which is closer to the ball. This method does not guarantee that you will gain possession of the ball.
Slide tackle
Although spectacular, slide tackling should not be used unless in desperation or when you're away from your own goal. It can also be very effective against opponents dribbling down the sideline or shielding the ball.