trace_pipe what are they/ is it file or some kind of channel that I can open and read and write to it | And what are Linux trace

Question

So I have this code

So I like to know what is this trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0); it seems like reading trace but what is trace so begin telling me something about trace, and can I read any trace/ how many traces are there. If I do a write on trace pipe then what other end is in the write system call. so I am awefully confused about word trace and let alone simple code below writing to trace_pipe. Can I create my own trace? How and please telll me this

void read_trace_pipe(void)
{
    int trace_fd;

    trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
    if (trace_fd < 0)
        return;

    while (1) {
        static char buf[4096];
        ssize_t sz;

        sz = read(trace_fd, buf, sizeof(buf) - 1);
        if (sz > 0) {
            buf[sz] = 0;
            puts(buf);
        }
    }
}