Is it the
.vmx files that are created on installing VMWare,
does it differs across Windows and Linux platforms as hosts?
How can we create or browse datastores when the host is Linux or Windows?
A datastore is an abstract container for virtual machine disks, and can be any supported storage medium (SAN, network share, local disk). From the VMware Virtual Infrastructure documentation:
How you would create and browse datastores depends on what VMware product you are using. For vSphere/ESXi, you can follow this guide.
The .vmx files are the primary configuration files for a virtual machine, and are plain text. You can view and edit them in any text editor. See this KB article for more information on the files associated with a VM.