From Laerd Statistics:

The Pearson product-moment correlation coefficient (or Pearson correlation coefficient for short) is a measure of the strength of a linear association between two variables and is denoted by r. Basically, a Pearson product-moment correlation attempts to draw a line of best fit through the data of two variables, and the Pearson correlation coefficient, r, indicates how far away all these data points are to this line of best fit (how well the data points fit this new model/line of best fit).

Yes.

The Pearson correlation coefficient ranges from -1 to 1 inclusive.

The sign of the coefficient tells you the kind of correlation:

• positive: as one variable increases the other also increases (like y = x)
• negative: as one variable increases the other decreases (like y = -x)

|r| = 1 means perfect correlation