A guide is a person who leads anyone through unknown or unmapped country. This includes a guide of the real world (such as someone who conducts travellers and tourists through a place of interest), as well as a person who leads someone to more abstract places (such as to knowledge or wisdom).

There are many variants of guides in this context, and guides are often employed in any aspect of travel or adventure, or wherever there is an advantage to the client in terms of knowledge provided in improving the overall travel experience or making the client feel more safe due to the presumed expertise of the guide.
These days guides will normally possess an area and field-specific qualification usually issued and/or recognised by the appropriate Guide's Association or licensing authority. However this is not always the case, and it is advisable for travellers paying a premium to go on an organised tour or journey because they think this will mean they will have a better experience to check the guide's qualifications beforehand.
Explorers in the past venturing into territory unknown by their own people invariably hired guides. American West explorers Lewis and Clark hired a Shoshone Indian woman Sacagawea, and Wilfred Thesiger hired guides in the deserts that he ventured into, such as Kuri on his journey to the Tibesti Mountains in 1938.
Aside from knowing the way or the area geographically, modern guides are usually hired to act as interpreters for those travellers who do not speak the local language and provide cultural, historical or other information on the area visited. Travel companies organising tours of large groups often have a guide or tour leader accompany the group. They might also be trained in First Aid and have other skills that reduce the risk for the tour operator to conduct these tours or the travel agency selling them.
Here are some examples of guide professions:

Maher Zain (Arabic: ماهر زين‎ ; born March 16, 1981 in Tripoli, Lebanon) is a Muslim Swedish R&B singer, songwriter and music producer of Lebanese origin. His debut album Thank You Allah, an internationally successful album with strong Muslim religious influences, was released in 2009. He released his follow-up album Forgive Me on April 2, 2012.

Maher Zain and his family moved to Sweden when he was eight years old. He completed his schooling there gaining a Bachelors degree in Aeronautical Engineering. After university he entered the music industry in Sweden and linked up with RedOne, the Moroccan-born Swedish producer.

When RedOne moved to New York in 2006 Maher Zain followed soon after to continue his music industry career in the USA producing for artists such as Kat DeLuna. On a visit home to Sweden he became engaged once more with his Islamic faith and decided to move away from a career as a music producer to become a singer/songwriter of contemporary R&B music with a strong Muslim religious influence.

Justin Randall Timberlake (born January 31, 1981) is an American singer, actor, and businessman. He achieved early fame when he appeared as a contestant on Star Search, and went on to star in the Disney Channel television series The New Mickey Mouse Club, where he met future bandmate JC Chasez. Timberlake became famous in the late 1990s as the lead singer and youngest member of the boy band 'N Sync, whose launch was financed by Lou Pearlman.

In 2002, he released his debut solo album, Justified, which sold more than seven million copies worldwide. The album was a commercial success, spawning the hits "Cry Me a River" and "Rock Your Body". Timberlake continued his success with his second solo album, FutureSex/LoveSounds (2006), debuting at number one on the Billboard 200 chart, and produced the US number-one hit singles "SexyBack", "My Love", and "What Goes Around... Comes Around".

Timberlake has won six Grammy Awards and four Emmy Awards. His first two albums made him one of the most commercially successful singers in the world, each selling in excess of 7 million copies. He also has an acting career, having starred in films such as The Social Network, Bad Teacher and Friends with Benefits. His other ventures include record label Tennman Records, fashion label William Rast, and the restaurants Destino and Southern Hospitality.

Mr. T (born Laurence Tureaud; May 21, 1952) is an American actor known for his roles as B. A. Baracus in the 1980s television series The A-Team, as boxer Clubber Lang in the 1982 film Rocky III, and for his appearances as a professional wrestler. Mr. T is known for his trademark African Mandinka warrior hairstyle,^{[citation needed]} his gold jewelry, and his tough-guy image. In 2006 he starred in the reality show I Pity the Fool, shown on TV Land, the title of which comes from the catchphrase of his Lang character.

Mr. T was born in Chicago, Illinois, the youngest son in a family with twelve children. His father, Nathaniel Tureaud Sr., was a minister. Tureaud, with his four sisters and seven brothers, grew up in a three-room apartment in one of the city's housing projects, the Robert Taylor Homes, in a poorly constructed building, in an area with high levels of environmental pollutants and the largest concentration of poverty in America. While growing up Tureaud regularly witnessed murder, rape, and other crimes, but attributes his survival and later success to his will to do well and his mother's love.

Fun (often stylized as fun.) is an American alternative rock band based in New York City that was formed by Nate Ruess, formerly of The Format. After the 2008 breakup of The Format, Ruess formed Fun with Andrew Dost and Jack Antonoff of Anathallo and Steel Train respectively. Fun has released two albums: their debut Aim and Ignite in 2009 and their latest Some Nights in February 2012.

The band is best known for its hit single "We Are Young" featuring Janelle Monáe. "We Are Young" reached number one on the U.S. Billboard Hot 100 and Digital Songs charts, becoming the first alternative song to top the Billboard Hot 100 chart since Coldplay's "Viva la Vida" in 2008. It also peaked at number one on the UK Singles Chart.

The Format split in February 2008. Immediately afterward Nate Ruess asked Andrew Dost and Jack Antonoff to join his new project. Dost had toured with The Format and provided various instrumentation. Ruess met Antonoff after The Format toured with Steel Train. The three began working together in New Jersey within a week. Ruess sang melodies while the other two provided music for them. The first demo song the band recorded was "Benson Hedges," which was made available for free in Spin's September 20, 2008 article on the band. Fun approached Steven McDonald, who produced The Format's album Dog Problems with Ruess, to produce their debut album. McDonald was enthusiastic about the project and stated, "I can’t believe what we’re working on here. This crushes anything I’ve ever done."