As the COVID19 cases start decreasing, some published articles mention that surgical masks are ineffective in protecting against the spread of viruses. However, there is evidence to show they help the wearer in terms of having a milder infection or not getting infected. This is because masks effectively reduce the number of viral particles that come into the wearer's body. However, wearing masks is primarily helpful in protecting others. When you breathe, cough, sneeze or talk, you expel droplets which become "droplet nuclei" when they evaporate. These smaller droplets are the ones that could infect someone else when you sneeze out. Masks are better at stopping droplets bigger than droplet nuclei; therefore, they are adequate to prevent the droplets before they evaporate into the surrounding air. 
A surgical mask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. Sharing surgical masks is not recommended. They may be sold as surgical, isolation, dental, or medical procedure masks.
Surgical masks are made in different thicknesses, which may prevent liquids from entering. These properties may also affect how easily you can breathe through the face mask and how well the surgical mask shields you. They are designed to help block large-particle droplets, splashes, sprays, or splatters that may contain germs (viruses and bacteria), keeping them from reaching your mouth and nose. Surgical masks may also help reduce exposure of your saliva to others. However, they do not provide complete protection from germs and other tiny contaminants because of the loose fit between the surface of the mask and your face.
It is not recommended to use a surgical mask more than once. If your surgical mask is damaged or soiled, or if breathing through the mask becomes difficult, you should remove it, dispose of it safely, and replace it with a new one. Wash your hands after handling the used mask.
What is Protective Mask - KN95 Masks KF94 Masks Singapore
KN95 masks are made from multiple layers of synthetic material (typically a polypropylene plastic polymer) and are designed to be worn over the mouth and nose. They feature a tentlike shape that creates a little space between your nose and the mask, making them somewhat easier to breathe through, less obstructive and concealing than N95s. They must filter out and capture at least 95 per cent of tiny 0.3-micron particles in the air (hence the "95" in the name), according to Shampa Chatterjee, PhD, associate professor of physiology at the Institute for Environmental Medicine and in the department of physiology at the University of Pennsylvania School of Medicine. 
KF94 masks started to be popular since the start of the pandemic. The "KF" stands for "Korean Filter", and the 94 refers to the masks' filtration efficacy. According to the South Korean government's standards, these masks filter 94% of particles down to 0.3 microns in size.  It can be said that KF94 Masks are the Korean version of N95 Masks. The regulations when wearing KF94 Masks are even more strict in South Korea. Like N95 masks, KF94s have an adjustable bridge that gives you a secure fit over the bridge of your nose. The side flaps help close the gaps around the face and limit unfiltered air entry," said Dr. Sara Andrabi, MD, assistant professor of emergency medicine at Baylor College of Medicine.