Jarablus is the northern-most city of Aleppo province in Syria. It was under ISIL occupation for a while. If you recall, in September 2016 (or probably end August), Turkish army along with some smaller bands of AQ (aka "FSA") launched the so-called Euphrates Shield Operations in Jarablus and took the city from ISIL. Within 24 hours Turkey bragged of "liberating" Jarablus. All that was a huge bluff. There were plenty of eye-witnesses including local activists and Kurdish-led Syrian Democratic Forces (SDF) who consistently confirmed that there was absolutely NO battle between Turkey and ISIL in Jarablus. The Turks took the city without a fight and with willing consent of ISIL because there were clandestine agreements between the two. Fighting took place only between the Turks and the Kurds after ISIL passed on Jarablus to Turkey. That's when the Turkish army and its AQ "FSA" allies went on a hostile spree clearing up villages around Jarablus area, driving out the Kurdish Democratic Union Party which is supposed to be the Syrian affiliate of PKK - Turkey's arch enemy. But there was definitely NO fight between ISIL and Turkey in Jarablus. This story was cleverly and deceitfully spun around by mainstream sources as "Turkish-backed Syrian rebels take Jarablus."
Despite being the closest friend of all AlQaeda terrorist factions, Turkey tries to put up a facade that the reason for its presence in northwest Syria is to curb terrorism for the security of Turkish borders. The world doesn't need to be told that Erdogani Turkey is a combination of radicalization, greed and ambition and wants to take advantage of the Syrian war to the fullest to grab as much Syrian territory as possible. And thus the shameless act of hoisting of the Turkish flag on Syrian soil.
Moreover, occupation of places like Jarablus and Al-Bab will help Tayyip Erdogan to prevent the Syrian Kurds from linking these strategic points with Kobane, also creating obstacles for the Syrian Army during future operations against ISIL in terrorist occupied Raqqa. Not to mention, all of this will further embellish his sweet dreams of a legendary sultan.
Syrian Free Press