In simple terms: It is a method of finding the best straight line fitting to the given dataset, i.e. tries to find the best linear relationship between the independent and dependent variables.
In technical terms: It is a supervised machine learning algorithm that finds the best linear-fit relationship on the given dataset, between independent and dependent variables. It is mostly done with the help of the Sum of Squared Residuals Method, known as the Ordinary least squares (OLS) method.
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