A guestbook is a paper or electronic means for a visitor to acknowledge their visitation to a site, physical or web-based, and leave their name, postal or electronic address (if desired), and a comment or note, if desired. Such paper-based ledgers or books are traditional in churches, at wedding

Wedding

A wedding is the ceremony in which two people are united in marriage or a similar institution. Wedding traditions and customs vary greatly between cultures, ethnic groups, religions, countries, and social classes...

s, funeral

Funeral

A funeral is a ceremony for celebrating, sanctifying, or remembering the life of a person who has died. Funerary customs comprise the complex of beliefs and practices used by a culture to remember the dead, from interment itself, to various monuments, prayers, and rituals undertaken in their honor...

s, B&Bs

Bed and breakfast

A bed and breakfast is a small lodging establishment that offers overnight accommodation and breakfast, but usually does not offer other meals. Since the 1980s, the meaning of the term has also extended to include accommodations that are also known as "self-catering" establishments...

, museum

Museum

A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities...

s and other private facilities open to the public. Many private homes also maintain guestbooks. Specialised forms of guestbooks include hotel registers, wherein guests are required to provide their contact information, and Books of Condolence, which are used at funeral homes and more generally after notable public deaths, such as the death of a monarch or president, or after a public disaster, such as an airplane crash.
On the Web, a guestbook is a logging system that allows visitors of a website

Website

A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...

 to leave a public comment. It is possible in some guestbooks for visitors to express their thoughts about the website or its subject. Generally, they do not require the poster to create a user account, as it is an informal method of dropping off a quick message. The purpose of a website guestbook is to display the kind of visitors the site gets, including the part of the world they reside in, and gain feedback

Feedback

Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...

 from them. This allows the webmaster

Webmaster

A webmaster , also called a web architect, web developer, site author, or website administrator is a person responsible for maintaining one or many websites...

 to assess and improve their site. A guestbook is generally a script

Scripting language

A scripting language, script language, or extension language is a programming language that allows control of one or more applications. "Scripts" are distinct from the core code of the application, as they are usually written in a different language and are often created or at least modified by the...

, which is usually remotely-hosted and written in a language such as Perl

Perl

Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...

, PHP

PHP

PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...

, Python

Python (programming language)

Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

 or ASP

Active Server Pages

Active Server Pages , also known as Classic ASP or ASP Classic, was Microsoft's first server-side script engine for dynamically-generated Web pages. Initially released as an add-on to Internet Information Services via the Windows NT 4.0 Option Pack Active Server Pages (ASP), also known as Classic...

. Many free guestbook hosts and scripts exist.

Names and addresses provided in guestbooks, paper-based or electronic, are frequently recorded and collated for use in providing statistics about visitors to the site, and to contact visitors to the site in the future.