Load your video, either enter a target bitrate directly or a target file size to calculate one, and export the file at that setting.
Bitrate is how much data is used per second of video, usually measured in kbps or Mbps. Higher bitrate means better quality but a larger file for the same length of video.
Enter your target size and the video's duration, and the tool works out and applies the bitrate needed to land close to that size — useful for meeting strict upload limits.
No. Resolution is the frame dimensions in pixels; bitrate is how much data describes each second regardless of resolution. You can have a small, low-bitrate 1080p file or a large, high-bitrate one.