What telement mean here and when it use it?

public List<TElement> SQLQuery<TElement>(string sql, string? connectionStringName = null, params StoredParameter[] parameters)
      {
          string ConnectionString = connectionStringName == null ? _ApplicationConfiguration.ConnectionString : _ApplicationConfiguration.GetConnectionString(connectionStringName);
          using (SqlConnection sqlConn = new SqlConnection(ConnectionString))
          {
              using (SqlCommand cmd = new SqlCommand(sql, sqlConn))
              {
                  cmd.CommandText = sql;
                  cmd.CommandType = System.Data.CommandType.StoredProcedure;
                  cmd.CommandTimeout = (int)TimeSpan.FromMinutes(5).TotalSeconds;
                  //cmd.Parameters.AddRange(parameters);
                  foreach (var parameter in parameters)
                  {
                      var paramter = cmd.CreateParameter();
                      paramter.ParameterName = parameter.ParameterName;
                      paramter.Value = parameter.ParameterValue;
                      if (!string.IsNullOrEmpty(parameter.TypeName))
                      {
                          paramter.SqlDbType = SqlDbType.Structured;
                          paramter.TypeName = parameter.TypeName;
                      }
                      cmd.Parameters.Add(paramter);
                  }

                  sqlConn.Open();
                  using (var reader = cmd.ExecuteReader())
                  {
                      var result = reader.MapToList<TElement>();
                      sqlConn.Close();
                      return result;
                  }
              }
          }