Overt and Covert are two English words that are often used together. Overt is an adjective word that describes an activity or operation that is done openly. Overt actions or operations are done without any need to conceal the intention behind it. On the other hand, covert has a meaning which is directly opposite in meaning to what overt stands for.
Covert is used mostly to describe activities or operations that are surreptitiously carried out. Covert means hidden, concealed, covered over. Other words that can be used as synonyms for overt are, open, plain, unconcealed, etc. Most times, overt and covert are used to describe human behaviors. Human behaviors are mostly judged by some actions that can be seen by other people.
These types of actions are overtly done, and that's why they can be seen by other people. However, there are some human actions that are hidden from people, i.e., Covert actions. These types of actions are the ones influencing those ones that are overtly observed by people.