How does raster scan works

Question

How does raster scan works? Describe briefly

Answer 1

Beginning from the top left corner of the screen, the electron gun scans (or sweeps) horizontally from left to right, one scan line which is one row at a time, jumping (devoid of tracing the line) to the left end of the next lower row till the bottom right corner is reached. Then it jumps (again devoid of tracing) to the top left corner and begins again, completing one full refresh cycle.

The main drawbacks of the raster scan is the jagged nature of the lines, occurring from the fact which the pixels are aligned all along regular columns and row, and points on line will not, in common fall on the accurate centre of the pixels.