why base 64 encode in swift code example

Example 1: convert string to base64 swift

import UIKit

extension String {

    func fromBase64() -> String? {
        guard let data = Data(base64Encoded: self) else {
            return nil
        }

        return String(data: data, encoding: .utf8)
    }

    func toBase64() -> String {
        return Data(self.utf8).base64EncodedString()
    }
}

Example 2: swift convert base64 string to data

var data = Data(base64Encoded: recording_base64, options: .ignoreUnknownCharacters)