Personal protective measures or the so-called "personal protective equipment" (PPE) is worn directly on the body and protects you from hazards that directly affect you. This includes, for example, protective goggles for work in the laboratory, hearing protection in the event of noise or fall protection when working at height.
Please note that PPE is less effective than, for example, trying to eliminate the source of danger completely, for example by substitution. Also check first whether technical (spatial separation) or organisational measures (temporal and spatial separation from the source of danger) can be considered before you reach for PPE.
One of the most important barriers against harmful substances is your own skin. You should protect your skin so that it can fulfil its task for a long time to come.