What is data validation? (in a simple definition)

Verify data, something like this

var username = document.getElementById("input1").value

var password = document.getElementById("input2").value

// this is the validation:
if ( username == "anime" && password == "Anime132" ){
alert("Correct login data");
} else {
alert("Wrong login data");
}

Data validation is a process that ensures the delivery of clean and clear data to the programs, applications and services using it.
(For a simple definition.)

It checks for the integrity and validity of data that is being inputted to different software and its components. Data validation ensures that the data complies with the requirements and quality benchmarks.
(Add this on if you want it longer.)

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