An adhesive label is a small piece of paper

Paper

Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 designed to be affixed to another larger piece of paper or other object, typically by the action of a layer of adhesive

Adhesive

An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

 on the back of the label.

The most familiar type of label is the postage stamp

Postage stamp

A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...

, which was developed in the mid-19th century. The concept has since been extended into a variety of areas:

• On mail:
  • airmail etiquette
    Airmail etiquette
    An airmail etiquette, often shortened to just etiquette, is a label used to indicate that a letter is to be sent by airmail. The term is from French étiquette "label, sticker" , from which also English etiquette "rules of behavior".- Use :Because the etiquettes are just instructions to postal...
    
    s
  • charity label
    Charity label
    A charity label is a label resembling a postage stamp, sold by charities to raise funds. They are generally intended to be used on mail, as a way of advertising the sender's support of the charity's cause....
    
    s
  • address labels
  • return address labels
  • postal meter labels
  • certain types of postal labels

• On other kinds of paper objects:
  • revenue stamp
    Revenue stamp
    A revenue stamp, tax stamp or fiscal stamp is a adhesive label used to collect taxes or fees on documents, tobacco, alcoholic drinks, drugs and medicines, playing cards, hunting licenses, firearm registration, and many other things...
    
    s
  • savings stamp
    Savings stamp
    A Savings Stamp is a stamp issued by a government or other body to enable small amounts of money to be saved over time to accumulate a larger capital sum. The funds accumulated may then be used to make a larger purchase such as taking out a savings bond or to pay a large upcoming bill...
    
    s
  • general markers, notices, or warnings

Almost every imaginable type of paper and adhesive has been used at some point; see postage stamp paper

Postage stamp paper

Postage stamp paper is the foundation or substrate of the postage stamp to which the ink for the stamp's design is applied to one side and the adhesive is applied to the other...

 and postage stamp gum

Postage stamp gum

In philately, gum is the substance applied to the back of a stamp to enable it to adhere to a letter or other mailed item. The term is generic, and applies both to traditional types such as gum arabic and to synthetic modern formulations...

 for a more detailed discussion. Label may be produced individually, or in sheets, which case they are usually separated by perforations or rouletting, see postage stamp separation

Postage stamp separation

For postage stamps, separation is the means by which individual stamps are made easily detachable from each other.Methods of separation include:# perforation: cutting rows and columns of small holes...

.