The HTML specifications have explicitly said that from the very beginning; the HTML 2.0 specification said: "HTML user agents should allow text to extend beyond these limits by scrolling as needed", and the current specification, HTML 4.01, repeats this more verbosely: This attribute specifies the number of visible text lines.
For these users, the 'valid' form of the textarea widget is a user-hostile control.
But if a "word" is longer than the textarea width, as set by the set to 20.
Your browser probably splits at least some of the strings to two lines.
Instead of allowing users to scroll horizontally, they "soft wrap": when line length would exceed the visible width, they display the text in two or more lines.
The actual data sent by the browser does not contain line breaks in such positions where the browser has "softly" broken a line; only actual line breaks entered by the user are included into the data.