This is a general term that people and businesses use for any type of graphic display that they use to convey information to people. This type of advertising has been around for thousands of years. Today most signage not only use words but often the words are combined with images. In the past signage many used only images. If the signage is for international viewers it will generally omit words completely.
The custom-made signs are generally designed for businesses to convey their location and name of the business. They can also be used to promote a specific product or service that a particular business offers. It can be as simple as a small sign that is hand-written and hangs in the window of the business to something as elaborate a bit of branding that is put together by a big-scale marketing company. This type of sign can be found on thousands of outlets of a single business. These signage usually comes in various sizes and shapes.
Many times custom-made signage is done to promote a business with their name but some of the most effect form of signage will have a central element beside the name, making the element or symbol iconic. One example is the signage for McDonalds Restaurant, which are the Iconic Golden Arches. They are as recognizable as their name. Their iconic Golden Arches are tall and can be seem from great distances. It also gives them branding opportunities that are limitless.
Street signage is another type that is geared to give information to drivers and pedestrians. Today many of the street signs that are seen in cities across the US have a green background with lettering that is done in white. They give the names of the actual streets and cross streets so to help people not familiar with the city to navigate their way around to various locations, businesses, and attractions. Because these types of signs primary goal are to let drivers and pedestrians know where they are the signs need to focus on legibility more than anything else.
Another type of street signage is instructional and hazard signs that can be seen throughout the world in most countries. These are the signs that need to be recognized easily from a far. For anyone that is driving or not familiar or speak the language they will generally feature some type of infographic or design theme that is comprehensible to everyone. For example, if it is a deer crossing signage it may show a road with a deer crossing it indicating that you need to slow down and watch for deer. One signage that is recognizable is the stop sign with its octagonal shape and red color.