Chromatic - Chromatic defines all twelve pitches in music. All 12 semi tones, or half steps, comprise the Chromatic Scale.

Diatonic - Diatonic Scales have five whole steps and two half steps. Examples include most major and minor scales.

Pentatonic - The Pentatonic Scale is based of off 5 notes.

Note that both the diatonic and the pentatonic can be viewed as coming from the Chromatic Scale, just skipping half steps simultaneously depending on the scale.
Definitions:
A "Tone" is the equivalent of moving two frets on the guitar. It is also known as a whole step.
A "Semi Tone" is the equivalent of moving one fret on the guitar. It is also called a half step.
The common moveable pattern is a scale, arpeggio, or specific finger placement that if moved on the neck can be repeated or played elsewhere on the instrument. With the exception of open position scales, or patterns that incorporate open strings, most single note patters on the guitar are common moveable patterns.

Note that there are several names for each position in a scale. There are also different symbols designed to identify a position in the scale. A capital "M" means major a lower case "m" means minor. Sometimes major notes and chords are understood to be major by their note name alone.
Lets look at the names of each position inside of the Chromatic Scale since they can be translated to the other types of scales.

First focus on these few reasons that practicing the scales develop both physically and theoretically
-Finger placement for the left hand
-Picking technique for the right hand
-The ability to ascend and descend with different patterns on the neck
-The understanding of notes being put together to play chords
Reading Guitar Tablature
Tablature Notation - A system of fret numbering developed throughout the Italian Renaissance for stringed instruments such as the early guitar and lute that allow you to play music by seeing the string and fret numbers. One of the ways music can be approached is through the understanding of sequential formulas and set whole and half step patterns. Since tablature uses fret numbers as the actual notes you read, it becomes very easy to make number/note associations. However, one major drawback to using this type of notation is that although advances have been made in recent years, there are no universally understood symbols to indicate rhythm, dynamics, or overall song structure used in guitar tablature. Secondly, as a result of Information Technology and widespread Internet access, unqualified transcribers often submit incomplete guitar tablature into the public domain. Sometimes the spacing of the fret numbers can give a simple suggestion as to what the rhythm may be. It is read left to right just like Lead Sheet Notation and many guitarists find it easier and less time consuming then studying lead sheet notation.
Each of these 6 lines below represents the six strings of your guitar in order and is read from bottom to top and biggest to smallest.
Place your finger on the fret of the string being indicated. Then with your right hand pick the note or series of notes.

Single notes are to be played individually left to right one after the other.

Fret numbers (notes) stacked vertically indicate a chord (discussed later) To play the chord place your fingers on the frets shown. Then strike all of the notes at the same time.

Playing the two octave major scale using the "Three Note Per String" perspective

Using the 2 octave Major Scale to build chord shapes

Use these exercises to become comfortable using the "three note per string" patterns.

A quick discussion of fret hand finger placement
Your finger placement should correspond to the spread of frets that you are playing over in an exercise, song, or passage. For example, when playing the previous progression using the three note per string perspective you should have started on your index finger, used your middle or ring finger for the frets between the highest and lowest in the pattern and reached the furthest notes with your pinky.
Note that the same fingering applied to a different area of the guitar can give you the same scale in a different key.
The two octave G Major scale

The two octave A Major scale

Top Secret Tips to Practicing Scales
Step by Step
Practice playing them exactly how they are written
(connect with what is on the page).
Play them up and then back
(ascending then descending-do not strike the low and high note twice).
Break them up four notes at a time
(continue up and back as stated in prior step).
Play each note 8 times before switching the next one
(mix the amount of times each note is struck).
Change the order of the notes, the amount of times you strike each, and mix them up.
The Common Scales
Major Ionian

Minor Dorian

Minor Phrygian

Major Lydian

Major Mixolydian

Minor Aeolean

Diminished Locrian

Chromatic

The Harmonic Minor Scale

The Melodic Minor Scale (descend in the natural minor)

The Minor Pentatonic Scale

The Asian Pentatonic Scale

The Blues Scale

The Byzantine Minor Scale

Dorian b2

Lydian Augmented

Lydian Dominant

Hindu

Locrian Natural 2

Super Locrian
