VNC gives you access to the entire RPi desktop. It is slower than SSH but a good option if you need to develop code while logged in remotely or view other windows (like camera output). It will ask for Username and Password.
Windows: Open MobaXterm (see Software). Click on the “Session” icon in the top left corner, and then on the icon that says “VNC”. In the “Remote hostname or IP address" field, type the IP address. Then click “OK”. It will ask for the password (see Username and Password). It will also automatically save your session, so you don't have to type the IP address again if you want to reconnect later. Instead, just double click the session in the pane on the left. If you don’t see it, make sure you are in the “Sessions tab” on the far left. Note that SSH sessions have a monitor icon.
If you are using RealVNC viewer instead, click on "File" in the top menu bar. In the new window that appears, enter the IP address in the "VNC server" field. After you press OK, a new icon with for your connection will have appeared in the RealVNC main pane. Double click on it to open the connection. It will ask for the password (see Username and Password) and after pressing OK, a new VNC window will appear for your remote connected. To end your connection, just close the VNC window. If you want to reconnect (to the same IP address), you can just double click the icon again.
iOS: Start the VNC Viewer program and where it says “Enter a VNC Server address or search”, enter the IP address.
If everything on the remote screen is too small, you may need to change the display resolution.
To change the resolution when attached to a monitor
Go to the main menu by clicking on the raspberry icon in the top left. Select Preferences - Screen Configuration. In the new window that appears, click on Layout, and then Screens - HDMR-1 - Resolution. Set it to the resolution you want. Click Apply. You now have 10 seconds to click OK, before it reverts back to the old resolution.
To change the resolution when using VNC in headless configuration
Open a terminal window on the raspberry pi and type:
sudo raspi-config
Select option "2 Display Options" and then "D5 VNC Resolution". Set it to a lower one (the default is 1920x1080). You navigate using tab and the arrow keys.