Bold

Bold Justification:

The human eye is very receptive to differences in brightness within a body of text. Therefore, you can differentiate between types of emphasis depending on whether the emphasis changes the "darkness" of text.

By contrast, the weight makes text bold darker than the surrounding text. With this technique, the highlighted text is strongly out from the rest, so it should be used to highlight certain keywords that are relevant to the topic of the text for easy visual scanning text. For example, printed dictionaries often use boldface for their keywords, and the names of the inputs can be conventionally marked in bold.

Why use;

The most common methods in Western typography fall under the general technique of care through a change or modification of the font:

for see the example how to apply click here