What is intercept term?

For a line graph, its equation is:

y = mx + c

where 'm' is the gradient of the line and 'c' is the intercept - which gives the value of y when x = 0.

In linear regression, the line of best fit (y = α + βx where α is the intercept-term) is found so that the distance of each point from this line is a minimum. Sometimes people will go for a simpler regression line which does not have the intercept-term, ie the line passes through the point (0, 0).