Counter to what the article that LH linked stated:

"The Taliban are one of the mujahideen groups that formed during the war against the Soviet occupation of Afghanistan (1979-89)."

Mullah Omar started his movement in 1994 (five years after the Soviets withdrew from Afghanistan) with less than 50 armed madrassah students, known simply as the Taliban (Students). His recruits came from madrassahs in Afghanistan and Pakistan and from the Afghan refugee camps across the border in Pakistan. They fought against the rampant corruption that had emerged in the civil war period and were initially welcomed by Afghans weary of warlord rule.

It first emerged early in 1994, when Mullah Mohammed Omar led 30 men armed with 16 rifles to free two teenage girls who had been kidnapped and raped by a local warlord's group; hanging the local commander from a tank barrel.

His movement gained momentum through the year, and he quickly gathered recruits from Islamic schools. By November 1994, Omar's movement managed to capture the province of Kandahar and then captured Herat in September 1995. Kabul fell to the Taliban on September 26, 1996. Omar stayed behind in Kandahar along with the Taliban elite, while a government of his loyal followers was set up in Kabul.

Now as his fighting force consisted of his pupils, what sort of age would they be? I would venture to guess that Mullah Omar's Taliban were too young to have fought the Soviets, or if they did were only involved in the dying stages of the occupation.

But one thing is for certain:

"The Taliban WERE NOT one of the mujahideen groups that formed during the war against the Soviet occupation of Afghanistan (1979-89)."