What is a VST or VSTi audio plugin ?

VST stands for Virtual Studio Technology and is an interface for integrating audio synths and effects plugins with your digital audio workstation (DAW). In plain English you could simply say its a way to get all those cool hardware effects racks, keyboards and drum machines into your choice of music software such as Cubase, FL Studio or Logic Pro etc.

A very brief history of VST & VSTi

Anyone making digital music prior to 1996 used their DAW to control keyboards and samplers via midi and then routed all their external hardware through a traditional mixing desk. With the release of Cubase 3.02 Steinberg announced the VST interface specification which allowed a new bread of software developers to recreate all those bulky effects units as VST plugins.
A few years later in 1999 they updated things allowing VST plugins to receive midi data. This changed the game even further as it was now possible to recreate keyboards, synths and drum machines too. This upgrade saw the birth of the Virtual Studio Technology Instrument or VSTi for shot.
In more recent years things have moved improved further with VSTs now being able to process audio in 64 bit, allow audio inputs, multiple midi ins & outs and note expression.

How Do you Install A VST plug in Or VSTi

Most VST plugins or instruments are packaged in one of two ways. Smaller plugins come as a single .dll file and are the simplest to install. Most DAWs such as Cubase, FL Studio require you to simply copy and paste the .dll file into a plugins directory within the main folder where you installed your software. Once you have done that you should restart your DAW and then your new plugin will be available to use.
Bigger, more complicated and often more expensive VST plugins and Virtual Instruments are often sold as .exe files that require you to manually install them the same way you would install any other software package. This is more often then not a point and click job though.

Are VST plugins and Instruments as good as the originals ?

There are 1000,s of VST plugins available these days and the quality varies greatly. Some have been made in an afternoon by one guy in his bedroom and given away for free and some developed by large companies and cost an arm and a leg. There are always those people who prefer the original instrument or prefer the hands on approach but in the majority of cases there is no way that many of us could ever get access to such kit. That old Hammond organ with Leslie speakers might be just the sound your after but its never going to fit in your room.
What the VST plugin and instrument developers have tried to do in many cases is to recreate the sound or effects of originals as closely as possible but you'll never get exactly the same experience due to one being real and one being virtual. With that said though VST technology has totally revolutionised the world of music production and it can only get better.
There are also plugins and instruments that could never exist in the physical world and the possibilities are endless.

What do I need in order to use VST plugins or instruments

Pretty much all you need to make use of VST plugins or Virtual Instruments is your choice of DAW. Just about every music production package available these days supports VST technology and many come with their own built in. In order to control things easier a good keyboard or controller is a must. A keyboard with weighted keys will give you more expression and a having controller with plenty of knobs and faders will allow you more control over all your plugins settings. There are plenty of excellent keyboards and controllers around these days to suit every budget so choose something the works for you.

Do I need a powerful computer to use a VST or VSTi

The one thing to take into consideration is that VST plugins and Virtual Instruments are software where their ancestors were all hardware. Your computer and more importantly your sound card is now playing the part of the hardware. Its all down to common sense to make sure you make the most of your current setup. If you try and get a cheap computer with a built in sound card to run too many VSTs it will drag to a halt. Ill write another article about how to improve performance but for now Ill just say uninstall anything you dont need and close any programs you dont need running.
The most important thing you need to get the most our or your VST plugins and Instruments is a decent sound card. Your sound card is going to be doing the bulk of the work so get the best one you can afford. A cheap sound card will result in a delay (latency) between you playing a note on the keyboard and the sound coming our of your VSTi. Make sure you ask for a card with zero latency or adjust the latency settings on your current card for best performance.
Finally Ill just mention again the need for you to balance your use of VST plugins, effects and Virtual Instruments with the power of your system. Too many things running at one time and you'll see your system slow down and your audio glitching.