Bresenham's algorithm and digital differential algorithm (DDA) are digital lines in drawing algorithms. They are usually used to draw pictures in computer graphics. A digital differential algorithm is usually used in computer graphics to draw a line, and it makes use of real values in predicting the next value of pixels.

Bresenham's algorithm was invented in the year 1962 by Bresenham, where it got its name from. It is a digital line drawing algorithm that uses addition and subtraction while drawing lines to compute the pixel value. It is very effective at drawing curves and circles too, and it is more accurate.

The DDA uses floating points together with the real values to make computations. It uses differential equations to get the next pixel or point values. Bresenham's algorithm, on the other hand, uses integer arithmetic. Thus, fixed constants are used in this algorithm, unlike the DDA.