On conventional sets, all the even-numbered lines (2, 4, 6, etc.) are displayed first, to be followed a fraction of a second later by the odd-numbered lines.

When video is sent in interlaced-scan format, each frame is sent as the field of odd-numbered lines followed by the field of even-numbered lines.

Then, the next time it moves down the screen it paints the even-numbered lines, alternating back and forth between even-numbered and odd-numbered lines on each pass.

It consists of an indefinite series (tirada) of verses, in which the even-numbered lines have a near-rhyme (assonance) and the odd lines are unrhymed.

Interlacing divides the frame into two fields, scanning alternately the odd-numbered lines and even-numbered lines.

For every frame, there are actually two incomplete images or fields, one for the odd-numbered lines of the image, and one for the even-numbered lines.

To reduce flicker, analog CRT TVs write only odd-numbered scan lines on the first vertical scan; then, the even-numbered lines follow, placed ("interlaced") between the odd-numbered lines.

In this case, positioning the even-numbered lines does require precise position control; in old analog TVs, trimming the Vertical Hold adjustment made scan lines space properly.

It refreshes the odd-numbered horizontal lines first and then the even-numbered lines.

The second half contains only the even-numbered lines.