Explanation
+ configuration file containing settings for a virtual machine such as guest OS: VMX
+ component of a virtual machine responsible for sending packets to the hypervisor: vNIC
+ zip file containing a virtual machine configuration file and a virtual disk: OVA
+ file containing a virtual machine disk drive: VMDK
The VMX file simply holds the virtual machine configuration.
VMDK (short for Virtual Machine Disk) is a file format that describes containers for virtual hard disk drives to be used in virtual machines like VMware Workstation or VirtualBox.
An OVA file is an Open Virtualization Appliance that contains a compressed, "installable" version of a virtual machine. When you open an OVA file it extracts the VM and imports it into whatever virtualization software you have installed on your computer.

Explanation
From the output we see DSW2 is running in RSTP mode (in fact Rapid PVST+ mode as Cisco does not support RSTP alone). When a new switch running PVST+ mode is added to the topology, they keep running the old STP instances as RSTP (in fact Rapid PVST+) is compatible with PVST+.

Sw1
Config t
Monitor session 20 source vlan 99 tx
Monitor session 20 destination interface ethernet 0/1
Copy run start
R1
Config t
Ip flow-top-talkers
Top 50
Sort-by packets
Cache time-out 30
Eth 0/2
Ip flow egress
Copy run start
Sw02
Config t
Ip sla 10
Icmp-echo 1.1.1.1 source-ip 172.16.2.2
Frequency 5
Threshold 250
Timeout 3000
Ip sla schedule 10 start-time now life forever
Copy run start

Explanation
The command "ip nat inside source list 1 interface gigabitethernet0/0 overload" translates all source addresses that pass access list 1, which means 172.16.1.0/24 subnet, into an address assigned to gigabitethernet0/0 interface. Overload keyword allows to map multiple IP addresses to a single registered IP address (many-toone) by using different ports so it is called Port Address Translation (PAT).