Loanwords are words borrowed from one language and incorporated into another without significant modification. These words often retain their original meaning and pronunciation but may be adapted to fit the phonological and grammatical rules of the borrowing language. In English, examples of loanwords include "sushi" from Japanese, "ballet" from French, and "piano" from Italian. Understanding loanwords helps language learners recognize and use these terms correctly and provides insights into the cultural and linguistic influences between languages.