Ultrafast electron diffraction (UED) is a rapidly advancing field, with a surge of scientific outcomes and significant progress in the development of high-brightness electron beams tailored for improved resolution and signal-to-noise ratios. In this talk, we will present recent developments in beam physics and technology aimed at producing beams with lower emittance, shorter bunch lengths, tighter timing synchronization, and better stability for UED, as well as for broader applications that demand high-brightness, precisely controlled beams.