When we test VPNs, we use the Ookla speed test tool. (Note that Ookla is owned by PCMag's publisher, Ziff Davis.) This test provides metrics for latency, download speeds, and upload speeds. Any one of these can be an important measurement depending on your needs, but we tend to view the download speed as the most important. After all, we live in an age of digital consumption.
Fortunately, there are some brave companies that are still trying to stay one step ahead of Netflix’s VPN catchers. Currently, Windscribe Pro is our top choice. The service delivers good speeds on its U.S. servers, and has a very simple approach to Netflix: Just select the “Windflix” connection from the desktop app or browser extension and you’re good to go. Windflix is still technically in beta, but it works well and there’s even a Windflix U.K. option if you’d like to experience Netflix from the other side of the pond.
Some VPNs will also let you define the specific context in which the VPN functions. TunnelBear VPN, in particular, lets you mark a network as trusted and will only activate when you're not connected to one of these trusted networks. This will protect you from bad guys, but it will leave you open to tracking and surveillance by governments and your ISP when you're on trusted networks.
However, network performance is another thing entirely. First, keep in mind that if you're using a VPN, you're probably using it at a public location. That Wi-Fi service is likely to range in performance somewhere between "meh" and unusable. So, just the fact that you're remotely working on a mediocre network will reduce performance. But then, if you connect to a VPN in a different country, the connection between countries is also likely to degrade network performance.
Mac users often told that they don’t need antivirus software because Mac is not prone to viruses; get a life man! This is not true at all, even the first well-known virus; Elk Cloner, affected Apple computers, not MS-DOS computers. Currently, the state of Mac malware is evolving, with more and more threats targeting the so-called impervious machines. We have already witnessed Mac threats appearance recently; on malwarebytes.com a mac user from Miami who had his DNS settings changed and were unable to change them back.
For PPTP and Layer Two Tunneling Protocol (L2TP), a tunnel is similar to a session. Both of the tunnel endpoints must agree to the tunnel and must negotiate configuration variables, such as address assignment, encryption, or compression parameters. In most cases, data transferred across the tunnel is sent using a datagram-based protocol. A tunnel management protocol is used as the mechanism to create, maintain, and terminate the tunnel.

Of course that brings up another problem. Since there are so many services to choose from, how can you tell which ones are worth using? PCWorld has taken care of much of the legwork with its Best VPN services roundup. [Spoiler alert: It found Mullvad to be a great all-around VPN for its above-and-beyond commitment to user privacy, and NordVPN to be the current choice for watching U.S. Netflix from abroad.]

IVPN is a Gibraltar-based VPN service whose primary USP is excellent security and privacy. It uses multi-hop technology that routes user traffic through a maze of networks to leave hackers scratching their heads should they attempt stealing your information. However, it offers inconsistent speeds with some servers operating quite fast, while others being slow.
While you're connected to a VPN, all your network traffic passes through this protected tunnel, and no one—not even your ISP—can see your traffic until it exits the tunnel from the VPN server and enters the public internet. If you make sure to only connect to websites secured with HTTPS, your data will continue to be encrypted even after it leaves the VPN.