Parallel (stylized in all caps) is the fifth extended play (EP) by South Korean girl group GFriend.

The EP was released digitally and physically by Source Music on August 1, 2017 and distributed by LOEN Entertainment.

The extended play was re-released on September 13 under the title Rainbow with the single "Summer Rain" and a bonus track of the same name.

[1] The EP also debuted at number 10 on the US World Albums chart, on the week ending August 19.

[2] The EP debuted at number 5 on the Gaon Album Chart, for the month of August 2017 with 61,473 physical copies sold.