iCloud backup process : apps like Facebook , Instagram

I purchased a new iPhone recently and I have completed the transfer process from my old iPhone to new iPhone .

I have not erased the data on my old iPhone yet . I would like to erase my iPhone. I saw that on your website what to do regarding iCloud backup in the process of erasing your phone before giving it , I have not backed my iCloud yet .

I want to know if apps such as Instagram , Facebook or Twitter will be comprised in the process . Everything is working on my new iPhone just like my old phone and it says app data can be backed up but I don’t want to be signed out of my social media apps . Please explain what does app data mean . If I choose not to back up app data will my social media be comprised .

Thank you for your answers in advance!