What is que sera sera?

Que Sera Sera is a phrase that comes from a Spanish-language song composed by Jay Livingston and Ray Evans. It was first introduced in the 1956 Alfred Hitchcock film, The Man Who Knew Too Much, where it was performed by Doris Day and became a popular hit. The phrase itself translates to "whatever will be, will be," and it has come to symbolize an acceptance of fate or an affirmation of the idea that the future cannot be predicted or controlled. It is often used as a motto or proverb in various contexts and has been referenced in popular culture numerous times.