Birdwatching, or birding, is the observation of birds as a recreational activity. That being said, there are all kinds of levels of involvement in this activity. Some will make a distinction between the two terms saying that birding is a more ‘serious’ activity than birdwatching. Birdwatching is also good for the economy and the environment (in general).
Some countries – small countries in Europe for example – have an activity called ‘twitching‘. It is a British term whereby a person will try to find a rarely observed bird, often traveling long distances. Ornithology is the scientific study of birds.

White-throated sparrow – Dunedin, PEI – May 31, 2017 – by John Read
White-throated sparrow, Dunedin (John Read)
Monitoring the birds involves the counting of species and birds within species as a means of assessing the health of bird populations. Many research centers have dedicated resources to maintain records of bird populations through the years. This helps decide whether to protect a bird by giving it a special status such as ‘threatened’ or ‘endangered’, etc., which then allows the allocation of funds for conservation.
Parts of this monitoring are the ‘bird counting‘ activities at different times of the year, for example the Christmas Bird Count and the Great Backyard Bird Count, and also the Bennett Birding Classic. In PEI birdwatchers can report their observations on a special mailing list distributed to participating members. Another counting activity is the Big Year, a competition in North America among birders where the goal is for participants to identify as many species of birds as possible within a given time. A comedy, The Big Year, was made about this activity.

Birding Code of Conduct: A CODE OF ETHICS or conduct has been established in the birding community to allow responsible bird watching without impacting the birds and their environment, for example by not approaching nesting birds too closely, and respecting all laws and private property. The Prince Edward Island Field Checklist of Birds has a list of five recommendations for bird-watching etiquette, which are specific to this Canadian province.

Bird Pishing: ‘Pishing’ means to imitate a bird sound or call in order to attract them. More information on this birding technique can be found here, including how to use it responsibly.

Bird Photography can be a professional or amateur activity. Feeding the birds is one way of attracting them close enough to photograph them. It is important to have a zoom and a tripod for good bird photographs. Binoculars are also an essential tool for birders. Photography equipemnt can easily become very expensive. Bird cams are becoming very popular too. Here’s a website dedicated to the observation of nesting birds via web cams: The hatching of these particular bald eagle eggs has apparently been viewed millions of times. The photographers below were patiently waiting for the first Japanese tit appearance in March. This bird is similar (in appearance) to the Black-capped chickadee.
Patient birders at the Kyoto Gyoen National Garden, Japan
Patient bird photographers in Kyoto, Japan