What is the name of the fastener that looks sort of like a screw and sort of like a nail?

I am starting in on a cargo trailer conversion and the first "screw" I attempted to remove (that fastens the plywood would the metal supports) would not thread out and I stripped it. I managed to extract it. It had a Phillips head, but it’s more like a nail.

I have seen other videos where owners have encountered these fasteners and said they are a pain to remove. But I haven’t found one that identifies it by name. Which would help in my search to identify the best way to extract these things.