Insert item in list using CSOM SharePoint

To insert item into list using csom code. You can create a consol application using visual studio and also use the code mentioned below. You can interact  with sharepoint list using JSOM,CSOM or using rest api.
List operation using csom.

using Microsoft.SharePoint.Client; 

using System; 

using System.Collections.Generic; 

using System.Linq; 

using System.Security; 

using System.Text; 

using System.Threading.Tasks; 

namespace ConsoleApp1 {
class Program {
static void Main(string[] args)
{
using (ClientContext clientContext = new ClientContext("insert url upto list"))
{
string Uname = "Your ID";
string password = "Password"; 

SecureString Securepasseord = GetSecureString(password); 

clientContext.Credentials = new SharePointOnlineCredentials(Uname, Securepasseord); clientContext.ExecuteQuery();

List oList = clientContext.Web.Lists.GetByTitle("metalist"); 

ListItemCreationInformation listCreationInformation = new ListItemCreationInformation(); 

ListItem oListItem = oList.AddItem(listCreationInformation); 

oListItem["Title"] = "This is title";

 oListItem["Keywords"] = "test"; 

oListItem.Update(); 

clientContext.ExecuteQuery();
}
}
private static SecureString GetSecureString(String Password)
{
SecureString oSecurePassword = new SecureString(); foreach (Char c in Password.ToCharArray()) { oSecurePassword.AppendChar(c); } return oSecurePassword;
}
}
}