Tell me, what is calibration and where is this word used?

Verification is the process of checking and confirming that measuring instruments meet established standards and requirements. Typically, verification is used in metrology to control the accuracy and proper functioning of devices such as scales, counters, and thermometers.

In programming, the word "verification" is rarely encountered, but in the context of Golang, it may refer to data validation or testing. In general, verification is the process of checking the correctness and compliance of something with specified norms.

An example in Go for validating data:

package main

import (
    "fmt"
    "regexp"
)

func isValidEmail(email string) bool {
    re := regexp.MustCompile(`^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$`)
    return re.MatchString(email)
}

func main() {
    email := "example@test.com"
    if isValidEmail(email) {
        fmt.Println("Email is valid")
    } else {
        fmt.Println("Email is invalid")
    }
}

Here, the string is checked (validated) for compliance with the email format — similar to data verification.