In brief
HTML section represents a standalone thematic section when no more specific semantic element fits. It should usually have a heading explaining its topic.
Useful to know
HTML section represents a standalone thematic section when no more specific semantic element fits. It should usually have a heading explaining its topic. [1]
If a container exists only for a background or spacing, section may be inappropriate. Read the page as a structure of topics before turning every visual stripe into a separate section.
Sources
For further detail and to check the information: