An expert.
Yes, the noun 'expert' is a common noun, a general word for any person with special skill in or knowledge of a subject.
Their knowledge of the subject.
The person have this subject in his or her graduation or in postgraduation.The person should have knowledge of genetics .
a person who has special skill or knowledge in some particular field
To gain more knowledge on the subject of interest - and share their knowledge with others.
a specialist
A "Chess Maven" refers to a person who has special knowledge or experience in chess ; an expert .
Lay knowledge refers to the knowledge held by non-experts or individuals who do not have formal training or expertise in a specific subject. It is based on common sense, personal experiences, and information gathered through everyday life rather than formal education or specialized training.
An ignorant person is often referred to as uninformed, uninstructed, or lacking knowledge or awareness about a particular subject or topic.
knowledge
If you're installing a new computer sound system, then you'll need some basic knowledge on the subject in order to succeed. It's important to make sure that the computer in question can support the new sound system.
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