A breakaway from terrorist organization al Qaeda, "Islamic State" is a Sunni militant group that is believed to have formed in response to disillusionment and frustration due to the failed rule of governments in Syria and Iraq. Its flag reads "Muhammad is the prophet of God" and "There is no god apart from Allah" - lines that are valid for all Muslims, not just "IS."

The "Islamic State" aims to create a "caliphate" - a state where the traditional values of Islam and Sharia law must be adhered to. Due to the instability of regions in Syria and Iraq, the "Islamic State" has been able to capture land in the two countries.

A key difference is the brutality "Islamic State" has used to strike fear into its enemies and innocents by cruel beheadings and ruthless violence. In contrast to this, it is said to govern the regions it takes over. As Middle East expert Shadi Hamid told PBS: "They provide social services. They run local government. They provide some modicum of law and order."

Though "IS" is active in Syria and Iraq, the Nigerian terrorist organization Boko Haram recently declared its support. It's like a competition in cruelty: while Boko Haram is responsible for 13,000 deaths, "IS" has injured or killed at least 24,000 people. Terrorist group al Qaeda has distanced itself from "IS" with its offshoot Nusra Front even fighting against "IS".

Something else that distinguishes the "IS" is its followers. More than 20,000 foreign fighters have joined the group, with more than 4,000 come from Western Europe and North America, according to an ICSR report. Here are the countries where most people have gone to fight. But, there are more fighters per capita heading to fight from some smaller countries like Sweden and Belgium.

Since August 2014, a US-led coalition has carried out airstrikes on "Islamic State" targets in Syria (1,422 strikes) and Iraq (2,242 strikes), according to a BBC report. Some governments have also been active within their own countries: Germany is set to prosecute at least 30 suspected militants returning from Syria, while Saudi Arabia, for example, arrested 93 suspected militants in April 2015.

A breakaway from terrorist organization al Qaeda, "Islamic State" is a Sunni militant group that is believed to have formed in response to disillusionment and frustration due to the failed rule of governments in Syria and Iraq. Its flag reads "Muhammad is the prophet of God" and "There is no god apart from Allah" - lines that are valid for all Muslims, not just "IS."

The "Islamic State" aims to create a "caliphate" - a state where the traditional values of Islam and Sharia law must be adhered to. Due to the instability of regions in Syria and Iraq, the "Islamic State" has been able to capture land in the two countries.

A key difference is the brutality "Islamic State" has used to strike fear into its enemies and innocents by cruel beheadings and ruthless violence. In contrast to this, it is said to govern the regions it takes over. As Middle East expert Shadi Hamid told PBS: "They provide social services. They run local government. They provide some modicum of law and order."

Though "IS" is active in Syria and Iraq, the Nigerian terrorist organization Boko Haram recently declared its support. It's like a competition in cruelty: while Boko Haram is responsible for 13,000 deaths, "IS" has injured or killed at least 24,000 people. Terrorist group al Qaeda has distanced itself from "IS" with its offshoot Nusra Front even fighting against "IS".

Something else that distinguishes the "IS" is its followers. More than 20,000 foreign fighters have joined the group, with more than 4,000 come from Western Europe and North America, according to an ICSR report. Here are the countries where most people have gone to fight. But, there are more fighters per capita heading to fight from some smaller countries like Sweden and Belgium.

Since August 2014, a US-led coalition has carried out airstrikes on "Islamic State" targets in Syria (1,422 strikes) and Iraq (2,242 strikes), according to a BBC report. Some governments have also been active within their own countries: Germany is set to prosecute at least 30 suspected militants returning from Syria, while Saudi Arabia, for example, arrested 93 suspected militants in April 2015.