paypal credit line question

please explain this to me like i’m 5, credit is terrifying to me. i have a great credit score and pay my credit card on time every month in full, i have no issues with this. i just splurged on something i’ve wanted for a while and paypal offered me to pay in 4 and pulled a hard inquiry on my credit. i was approved and used pay in 4. i know ill be able to pay for this and am not worried about that. my question- is this a credit card? where if i dont continue to use this after this one big purchase it might impact my score? i use paypal frequently so its not the end of the world if i need to use the credit line to keep my score from being impacted but i cant find the answer in their FAQ they emailed me when i was approved.