RAM memory and VMware

Hello,
I don't have much experience with virtual machines and this question is probably trivial to you, but I need to know how to properly allocate memory for VM. I have never used vmware before and I saw a tutorial about installing new guest Os in VMware. The most interesting step is defining memory that VM would use. So, if the host computer has 4GB of RAM (example) and I define 2GB for VM, does it means that only 2GB is left for host whether VM is running or not? In other words, does host OS have less memory because of guest OS even when VM is powered off?

Thank you!

The vm only uses memory when its running that o/s

When you install VMWare and set up your virtual machine, just stay with the defaults that are suggested by VMWare.

I have 4 GB of RAM in my computer, and I recently installed VMWare and set up VMs for Windows 7 and Windows 8.1. I stayed with the defaults that were suggested by VMWare. When I have one of the VMs running, the VM is a bit slow sometimes, but the host system (Linux Mint) works fine.

If I had more than 4 GB of RAM in the computer, I would increase the RAM which is available to the VMs. But for now, I'll just leave it as it is.