There are many reasons, here are just a few.
They believe it is the only way they will be listened to.
They want power and to impose their views on others.
They believe they are being persecuted.
They are insane.
Because they can.
Terrorists use explosives and demonstrations to prove a point. Each terrorist group has it's own beliefs and methods to accomplish their goals. For example Eco-Terrorist groups sabotage equipment and chain themselves to trees to prevent bulldozing. Religious Extremist groups often use high explosives, suicide bombers, theft, vandalism, and kidnapping in order to finance and further their cause. All terrorist groups use guerrilla tactics in order to function, which means they hide among the public and do not wear any specific uniform often.
about peace they both are the same and also both have some extremist groups.
Yes. Unfortunately, most religions and cultures have some people with extremist beliefs. See the related link below for a bit more.
There are a number of left-wing terrorist organizations, such as FARC in Colombia, the Japanese Red Army, Shining Path, and Eco-Terrorist Groups.
The Taliban and Al Quaida
Not all Muslims are classified as extremists or terrorists, but some are. It is important to note that the majority of terrorism and mayhem in the world stems from Islamist/Muslim extremists.
Some of the terrorist groups operating in Libya include ISIS, Al-Qaeda in the Islamic Maghreb (AQIM), Ansar al-Sharia, and the Benghazi Defense Brigades. These groups have been involved in various attacks and violent activities in the country.
Some domestic terrorist groups that flourished during the 1960s and 1970s in the United States include the Weather Underground, the Symbionese Liberation Army, and the Black Liberation Army. These groups carried out bombings, kidnappings, and other violent acts in pursuit of their revolutionary ideals.
Yes. Bomb residue has already been confirmed and some terrorist groups are trying to take credit.
Broadly defined, an extremist activity is an activity that is removed from what would be considered ordinary. Some would consider skydiving an extreme activity.
A terrorist bombed the marketplace."Was it a terrorist?" people asked after the bombing.The defendant insisted he wasn't a terrorist.
There are many reasons for this. It is most often blamed on religious texts, and while misinterpretation may be partially responsible, it is not the whole truth. A lot of it has to do with the idea that the West (the US in particular) has the best governing practices and also the West's inferred desire to force their ideologies upon other (non-Western) countries. Many extremist groups are about resisting the West and preserving tradition, however terrible their methods might be.