On the next page of the guide to Genshin Impact you will find out what the Original Resin is, how to get it, when it is renewed and what it is for.
The Original Resin is a material that is primarily used for getting treasure. These treasures are available primarily after defeating a given boss, after opening Ley Line Outcrops and defeating a wave of mobs, and in certain Dungeons. 1 Original Resin is renewed every 8 minutes, but cannot renew above 120.
Original Resin can also be restored by using Primogems. Renewing 60 Original Resin will cost 50 Primogems. If you have a Fragile Resin item in your equipment, you will also get 60 Original Resin after using it. However, it is worth noting that if Original Resin is renewed with Primogems, this cost will be increased. For the second and third time, the cost would be 100 Primogems, for the fourth time, 150 Primogems, and for the fifth and sixth time, 200 Primogems. You can renew Original Resin up to 6 times in one day.