Direct traffic is the category into which analytics places visits with no recognised source. Part of them really are people who typed the address manually or used a bookmark, which is a good signal of brand awareness. A significant part, however, belongs elsewhere and ended up in direct traffic for technical reasons: a click from a document, an email client or an app that does not pass on the source, moving from a secure page to an unsecured one, lost parameters during a redirect, or untagged links in the company's own campaigns. An unusual increase in this channel is therefore more often a sign of a measurement error than of growing awareness. The share of unrecognised visits can be reduced through consistent link tagging and checking redirects. It is therefore worth tracking mainly its share over time, not the absolute number.
See also: UTM parameters, Channel grouping, Brand Awareness.