Lime juice is the juice of any one of a number of cultivars of the lime, a greenish fruit with a sour pulp and acidic juice. There are many different types of lime, with the most common being:

Citrus latifolia, also known as the Persian lime, the Tahiti lime, and the Bearss lime (after John Bearss, who developed it in 1895). These are the most common supermarket limes, and are seedless.

Citrus aurantifolia, also known as the Key lime or Bartender's lime. These are smaller and more yellow than the Persian lime, with many seeds and are not only highly acidic, but also interestingly bitter at the same time. 

Citrus hystrix, also known as the Kaffir lime, or Makrut lime. These are about as small as the Key Lime, but have a warty skin and are intensely sour. The kaffir lime (both zest and especially leaves) are commonly used in Malaysian and Thai cooking, but the juice is more commonly used as a cleanser. 

All lime juice is sour, having a pH of between 1.8 and 2, which makes it more sour than lemon juice. For cocktail usage, the lime's strong green, grassy aspect works well with herbal flavors (think gin and Green Chartreuse). It is not as neutral of an acidifier as lemon juice. 

Some popular cocktails containing Lime juice

  • Paloma Sangria — White wine, Blanco tequila, Grapefruit juice, Lime juice, Simple syrup, Salt
  • Original Pisco Sour — Pisco, Bitters, Gomme syrup, Lime juice, Egg white
  • The Secret Is in the Telling — Rum, Falernum, Lime juice, Simple syrup
  • Arrackiri — Batavia Arrack, Herbal liqueur, Mezcal, Lime juice, Agave syrup, Bird's eye chile tincture, Cucumber
  • Hawaii Kai Treasure — Puerto Rican Rum, Curaçao, Crushed ice, Lime juice, Grapefruit juice, Half-and-half, Orgeat, Honey syrup
  • Black Bowtie Gimlet — Gin, Bitters, Salt Solution, Lime juice, Simple syrup, Squid ink
  • Medicinal Sour — Herbal liqueur, Suze, Absinthe, Lime juice, Lemon juice, Anise syrup
  • The Antioxidant — Cranberry Vodka, Aperol, Tangerine juice, Simple syrup, Lime juice, Strawberry, Orange peel
  • Rye-Tai — Rye, Triple sec, Lime juice, Orgeat, Lime
  • Cuban Anole — Rhum Agricole, Jamaican rum, Barbados Rum, Lime juice, Orgeat, Cinnamon syrup, Cinnamon