The pedal or "stompbox" because it is more affectionately known, is the most common form (as well as guitar die-hards essentially the most desirable) of guitar effect unit.
An average arrangement for the stompbox will contain a metal box encasing the unit's circuitry, along with which will be a footswitch to turn the effects on or bypass it, along with more than one rotary controls to vary the parameters with the effect. Somewhere in the unit you'll usually find an input jack for your signal from your guitar, along with an output jack on the other instrument, that can carry the signal on out of your unit and so on to the amp or some other unit.
Stompboxes might be chained one by one (i.e. the output in one unit leading into the input to an alternative), with the last output from the chain commencing your amp. As these units typically (although not always) only incorporate one sort of effect each (i.e. one box for distortion, one for chorus, one for compression, etc) you can use this method to incorporate several different effects in your guitar sound, layering up or lowering the quantity of effects by switching the boxes off or on via their footwitches.
Increasing a collection of quality stompboxes and using them by doing this is one thing that's highly coveted by a lot of guitarists, as they are able select precisely what they desire, unit by unit, giving them near total control on the shaping with their sound. Nevertheless it's only one best option, but more on that shortly.
The volume of pedals produced both past and provides for assorted different effect types is just too big massive to get in real detail here, although some people might well known brands and models you may want to look at to offer you an idea of what's available are; BOSS (DS-1 Distortion, CH-1 Super Chorus, DD-7 Digital Delay), Electro Harmonix (Memory Man, Big Muff, Small Clone), MXR (Phase 90, Dyna Comp), and DigiTech (Hot Head, DigiVerb, Multi Chorus).
Having see the above, a few of you might be feeling a tad disenchanted. Even allowing for the simple fact you might be buying budget pedals, you might turn out spending a fair amount of time and cash getting all of the ones you wish to craft your sound. Will there be no chance of mixing a whole pile of effects into one unit? There exists indeed, by means of multi-fx units.
Multi-fx units are available in many shapes, sizes and prices, however a standard one that will replace numerous stompboxes would have been a floor unit, including a few footswitches and selectors. Most over a certain price will also have an expression pedal, which you can assign as being a wah-wah pedal or volume swell, or indeed with other parameters.
Most modern examples will even begin to add some way of "amp-modelling" - that is circuitry from the unit designed to simulate different types of guitar amp, enabling you to do away with an actual physical amp altogether and play by way of a pair of conventional speakers. Additionally it is a handy setup for recording since you can record direct to your recorder (say, your computer's soundcard) without first having to mic increase guitar amp.
Some situations of the type are, the BOSS ME & GT series, the queue 6 POD XT (Line 6 were pioneers in the area of amp modelling), the Vox Tonelab series as well as the Zoom G series.
Many though believe such a unit is really a compromise, and you simply won't have the tonal quality beyond them that you'd with a set of individual effects pedals. The jury's out on that in terms of I'm concerned. There is not any doubt they have got greatly improved with time and can keep doing so.
From the trying an earlier example from Zoom. I was impressed with the ability to combine many effects into one small unit, even so the results weren't particularly great. Overdrive and distortion tones especially were a true problem since they lacked any of the warmth you'd receive from a conventional amp or effect pedal, and had a harsh 'digitised' sound. Compare that on the units Zoom and others now produce and so they seem a world away from those, with hindsight, primitive examples.
One thing's without a doubt, you certainly get yourself a much more bang for your buck today, in comparison with after i bought my first electric. Previously the premium brands, including BOSS and Electro Harmonix dominated, and with valid reason - the budget alternatives were cheap and not particularly cheerful.
That's fast changing though, so with the budget-conscious in mind I'll create a few recommendations.
Firstly I would like to point you towards Behringer's selection of stompboxes. These cover all you will most probably need with regards to overdrive, distortion, modulation, compression, delays and reverbs. I currently use the Behringer CS400 Compression/Sustainer inside my setup and am very happy with the results. The majority of these pedals are currently priced new for less than 30 (about 50 USD) each, so they're a smart way of getting started your collection.
Plenty of debate rages on the internet and elsewhere about the merits you aren't of those pedals. Surely something priced so low cannot match the standard of much higher-priced units? Well, perhaps they don't really quite match them, but as I discussed above the value for money factor the following is pretty amazing. Behringer house they in durable plastic instead of the metal cases additionally used for stompboxes, which can be probably step to keeping costs down. It won't follow though this could make them sound worse.