What is the meaning of Emphasis?

Special weight or forcefulness given to something considered important.

Special attention or prominence given to something.

Prominence given to a syllable or words, by raising the voice or printing in italic or underlined type.

The phonetic or phonological feature that distinguishes emphatic consonants from other consonants.

The use of boldface, italics, or other such formatting to highlight text. (Can we add an example for this sense?)

emphasis

Source: wiktionary.org