Model Representation

$m$ : number of training examples
$x$ : input variables / features
$y$ : output variables / target variables
$(x,y)$ : single training example
$(x_i,y_i)$ : $i^{th}$ training example

Training set to learning algorithm to hypothesis $h$ (based on size of house) to estimates price

$h_\theta (x) = \theta_0 + \theta_1 x$
$\theta_i$ : parameters

Linear regression in one variable = univariate linear regression