Wearing a sweater over a dress shirt
Recently, there is a trend of wearing a sweater over dress shirts (and under jackets). It is called "in-line layering." This means that you wear more than one layer of garments on top of each other.
This trend was born in the business world. The point is to create an office style that still looks stylish . The classic suit is perfect for formal occasions. But when you wear a suit outside of the office, it can look too much like "a uniform." In-line layering add some variety to your work outfits.
It was also born among young adults . For example, if someone goes on a date with his girlfriend. If he just wears a dress shirt and a suit, the shirt will look too formal. The sweater on top of it is more casual and less likely to make the girl feel uncomfortable . It also helps keep him warm at outdoor restaurants or cafes on chilly days.
But in-line layering can be used by anyone who wants to add variety to their outfits. For example, if someone wears a suit and tie to work every day. To make the look more stylish and less like a uniform, they can wear an unbuttoned dress shirt with a sweater instead of a blazer...