StrengthsFinder (or Now, Discover Your Strengths) is a self-help book written by Marcus Buckingham and Donald O. Clifton, first published in 2001. At the heart of the book is the internet based "Clifton Strengths Finder," an online personal assessment test that outlines the user's strengths. The authors advocate focusing on building strengths rather than focusing on weaknesses.
The theory behind the book is that each adult individual possesses a certain number of fixed universal personal-character attributes, defined by the authors as "talent themes," which, together, result in an individual's tendency to develop certain skills more easily and excel in certain fields in a sustainable way while failing or not being able to sustain success or high levels of effectiveness in other fields.
The authors claim that by identifying the individual strength of the members of the organization, its members can be utilized in more suiting positions, hence developing the required skills easily, helping to reduce turnover, improve employee morale and the organization's overall performance.
Source: https://en.wikipedia.org/wiki/Now,_Discover_Your_Strengths