VMWare: What is NAT vs. Bridged vs. Host-Only?
Host-only only permits network operations with the Host OS.
NAT mode will mask all network activity as if it came from your Host OS, although the VM can access external resources.
Bridged mode replicates another node on the physical network and your VM will receive it's own IP address if DHCP is enabled in the network.
Same concept as the normal network setup :)
Host-Only: The VM will be assigned one IP, but it's only accessible by the box VM is running on. No other computers can access it.
NAT: Just like your home network with a wireless router, the VM will be assigned in a separate subnet, like
192.168.6.1is your host computer, and VM is
192.168.6.3, then your VM can access outside network like your host, but no outside access to your VM directly, it's protected.
Bridged: Your VM will be in the same network as your host, if your host IP is
172.16.120.45then your VM will be like
172.16.120.50. It can be accessed by all computers in your host network.
While the other answers here provide good descriptions for the NAT and Bridged modes, their explanations for Host-only mode are not quite accurate.
From VMware's documentation, under Configuring Network Connections > Understanding Common Networking Configurations:
Host-only networking creates a network that is completely contained within the host computer. Host-only networking provides a network connection between the virtual machine and the host system by using a virtual network adapter that is visible on the host operating system.
Note that it does not say that the VM will be accessible only by the host. The network is self-contained, not the connection. This is a subtle but important difference.
Additionally, as pointed out by user5389726598465, under Creating Virtual Machines > Preparing to Create a New Virtual Machine > Selecting the Network Connection Type for a Virtual Machine:
With host-only networking, the virtual machine can communicate only with the host system and other virtual machines in the host-only network. Select host-only networking to set up an isolated virtual network.
You should be aware that the Host-only, NAT, and Bridged modes are aliases to specific virtual networking switches ("VMnets") that are preconfigured for the different behaviors. As with a normal network switch, all machines connected to the same switch are visible to each other.
This means that all VMs connected to a host-only network will be visible to the host and to each other. If you want a VM that is visible only to the host, you will need to assign it a dedicated VMnet and avoid assigning any other VMs to that VMnet.
The following table, from the Virtualbox documentation site, shows the connectivity between the VM and the Host for different network types: