In addition to mid-18th century battles during the French and Indian War, you will occasionally find yourself in modern world inside Abstergo Industries. The main story missions will send you in the Abstergo building, where you can collect different collectibles like tablets or reboot computers.
In order to reboot servers you have to line the beams to the segment of the core. You have to move the circles in such a way that each segment is powered by beam. The tricky part is that you can connect one beam per one core segment. When everything is lined up properly the computer system will reboot.