The Resistance is a fictional military organization depicted in the Star Wars universe that first appeared in Star Wars: The Force Awakens. Approximately thirty years after the Battle of Endor, the Resistance, a private army aligned with the New Republic, is at war with the First Order, a military junta built on the legacy of the Galactic Empire.
The Resistance derived from the Rebel Alliance that fought the Galactic Empire three decades earlier. It adopted the Rebel Alliance starbird as its insignia, utilizes the Incom T-70 X-wing fighter (a descendant creation of the Rebellion's T-65 X-wing fighter), and has former Rebellion fighters among its ranks, such as General Leia Organa, Chewbacca, Han Solo, C-3PO, R2-D2, Gial Ackbar, and Nien Nunb. Its best pilot is said to be Poe Dameron, leader of Black Squadron. The Resistance later finds allies in Finn, a defected stormtrooper of the First Order, and Rey, a Force-sensitive scavenger from Jakku.
Sometime after the Battle of Jakku, the First Order, an organization formed by the remnants of the Empire, became known to the public, most members of the Galactic Senate, led by Chancellor Lanever Villecham, did not take them very seriously, partly due to them being small in numbers and mainly because they believe the First Order would follow the tenants of the Galactic Concordance; however, Leia Organa founded a military organization known as the Resistance, to defeat the First Order.
As she along with most members of the Senate took that organization very seriously, also most members of the Senate were secretly funding and supported the Resistance, as they knew if the First Order was left unchecked, that organization would not only eventually destroy New Republic, but everything they have worked hard to rebuild, well other members of Senate do not openly support the Resistance, they at least tolerate that military organization's actions.