N95 masks are considered the gold standard in personal protective equipment because they block 95% of large and small particles utilizing a unique electrostatic filter

CNN

Cloth face masks can provide a barrier to respiratory droplets... N95 respirators, on the other hand, are medical-grade masks that filter 95% of small (.3 micron) particles and are far more effective.

Business Insider

Researchers found N95 respirators were most effective in filtering out particles. Those masks had a droplet transmission rate of less than 0.1 percent.

Duke University Study on Mask Effectiveness