Depending on who you ask, the Morphin Grid is either the source of the Rangers' powers or a storage facility for said powers. And according to the writers, what the Morphin Grid is and can do is different.
In Mighty Morphin, Zordon mentioned the Morphin Grid as the source of their powers. It was mentioned by Lord Zedd that the Morphin Grid is maintained by a balance between major forces of good and evil--which was Zordon and Zedd at the time. We never really "saw" it. In the show, Zordon would tap into it to boost up Tommy's powers. In the comics, Zordon enters the Morphin Grid to visit the Emissaries Three. In the 2017 movie, the Morphin Grid is a major plot point in which Zordon uses it to bring Billy back to life. The show never mentioned it to have life restoring powers. Even though Alpha was able to tap into the grid also to grow flowers.
In 2004, in a DVD extra Kira and Ethan are visited by the Morphin Grid to preview SPD. This is considered non-canon for fans. Kira and Ethan are at Hayley's restaurant where they find a big glowing green rock coming out of the building. It even spoke.
In 2007, for Operation Overdrive episode "Once a Ranger," Alpha 6 (Even though he acted and spoke like Alpha 5) says he needs to enter the Morphin Grid and it looked technological physical place. It had a green hue and it had lightning striking everywhere. Alpha 6 was able to fix it and restore the Rangers' powers.
Spoilers below.
