go-ethererm包networkID和chainID的区别？

代码中看到描述如下

// NetworkID returns the network ID (also known as the chain ID) for this chain.
func (ec *Client) NetworkID(ctx context.Context) (*big.Int, error) {
   version := new(big.Int)
   var ver string
   if err := ec.c.CallContext(ctx, &ver, "net_version"); err != nil {
      return nil, err
   }
   if _, ok := version.SetString(ver, 10); !ok {
      return nil, fmt.Errorf("invalid net_version result %q", ver)
   }
   return version, nil
}

但实际上client.NetworkID和client.ChainID拿到的返回值不一样，有没有大佬解释一下？

包版本v1.10.18