A WEB-DL (Direct Download) is typically higher quality because it is remuxed directly from the original stream without re-encoding. A WEBRip is often re-encoded to reduce file size, sometimes losing a small amount of visual fidelity. For most viewers on a 1080p monitor, the difference is negligible.
This refers to the video compression codec used to encode the file. Lethal.Seduction.2015.1080p.WEBRip.DD5.1.x264-BDP