Very casual. Talks about things highlighted in resume and some basic technical questions. Mostly important is not be able to present yourself

I was contacted by an HR rep about scheduling an interview, after many back and forth emails I interviewed with my direct supervisor and a manager on the team. They got back to HR on hiring decisions by the end of the week and HR was in contact with me a few days later to provide info for a background check. After the background check information approximately two days later I was emailed by HR asking me for a time and number to contact about an offer.