The Taliban is a group of terrorists who began committing acts of violence in other countries as far back as 1994. At this time is was simply a militia and then grew to become the insurgency it is today. Mostly the Taliban covered Afghanistan and cause the civil war in that area. ISIS is the Islamic State of Iraq and Syria. Both of these groups are very dangerous. Even though the Taliban is still considered to be present and active today, it is not heard about much anymore.
Instead, ISIS is the group that has gained power more recently in the past few years. However, due to the strength of many powerful countries, they have been able to fight ISIS so that they are diminishing in numbers.