Question

How do headings affect meaning in a technical text?

Answer 1

If I understand correctly as to what you are asking, headers help organize a piece of writing/text so that the reader can skip over parts of the text that they don't need/want to read and find the parts that they do need/want.

Answer 2

Headings affect meaning in a technical text because they highlight the main ideas in the text.

Headings are an important feature of professional technical writing. Since headings are the titles and subtitles that can be seen within the actual text of professional technical writing, they alert readers to upcoming topics and subtopics. Consequently, headings help readers to realize if they are interested in the topic of the text or not.

In addition, headings are also useful for writers because they help getting organized and focused on the topic.