Конструкция try / catch - в чем ее суть? - C#

public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        public double a, b, k, p, q, r, s, t;
        public int n;
        public double f1(double x)
        {
            return k / x;
        }
 
        public double df1(double x)
        {
            return k * Math.Log(Math.Abs(x));
        }
 
        public double f2(double x)
        {
            return p * x * x + q * x + r;
        }
 
        public double df2(double x)
        {
            return p * x * x * x / 3 + q * x * x / 2 + r * x;
        }
 
        public double f3(double x)
        {
            return s * Math.Cos(t * x);
        }
 
        public double df3(double x)
        {
            return s / t * Math.Sin(t * x);
        }
 
        public delegate double Func(double x);
 
        public double sqr(Func f)
        {
            double h = (b - a) / n;
            double res = 0;
            for (int i = 0; i < n; i++)
            {
                res += f(a + i * h + h / 2);
            }
            return h * res;
        }
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                a = Double.Parse(textBox1.Text);
                b = Double.Parse(textBox2.Text);
                n = Int32.Parse(textBox3.Text);
                if ((a < b) & (n > 0))
                {
                    if (radioButton1.Checked)
                    {
                        k = Double.Parse(textBox4.Text);
                        textBox10.Text = sqr(f1).ToString();
                        textBox11.Text = (df1(b) - df1(a)).ToString();
                    }
 
                    if (radioButton2.Checked)
                    {
                        p = Double.Parse(textBox5.Text);
                        q = Double.Parse(textBox6.Text);
                        r = Double.Parse(textBox7.Text);
                        textBox10.Text = sqr(f2).ToString();
                        textBox11.Text = (df2(b) - df2(a)).ToString();
                    }
                    if (radioButton3.Checked)
                    {
                        s = Double.Parse(textBox8.Text);
                        t = Double.Parse(textBox9.Text);
                        if (t != 0)
                        {
                            textBox10.Text = sqr(f3).ToString();
                            textBox11.Text = (df3(b) - df3(a)).ToString();
                        }
                    }
                }
                else MessageBox.Show("Введены некорректные данные.");
            }
            catch
            {
                MessageBox.Show("Введены некорректные данные.");
            }
        }
 
        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }