According to VSEPR theory, molecules adjust their shape to minimize the effect of repulsion.
Suppose I take the structure of $\ce{ClF3}$. It has three bond pairs and two lone pairs. So to minimize the repulsion it gets T-shape (the two lone pairs are at corners of a trigonal bipyramidal shape).
But my doubt is why do we call two lone electrons a lone pair? I mean, if we keep a lone pair at some point in a molecule, how can two lone electrons be so near? Why don't we take electrons individually but always lone pairs?