Speed is simply how fast a character can move in a given amount of time. There are three types of speed used for VS purposes: Combat Speed, Reaction Speed and Travel Speed. The term "Speed" is normally referred to Combat Speed.
The speed at which an attack moves. For example, X character is hypersonic, but he can do an attack that is a natural beam of light, the speed for the attack is different from the speed of the user, hence the attack would be lightspeed even if its user isn't.
The speed at which a character can fight.
The speed at which a character can react. This usually only grants a short movement upon reaction, several movements at the same speed switch it to combat speed. Say character A shoots at character B with a gun and character B dodges. That's their reaction speed. Keep in mind, sometimes a person aim dodges and it's not as good of a feat. For example let's say character A uses a minigun on character B, but the minigun takes a second or two to charge up and Character B see's this. If Character B dodges it's considered aim dodging since he/she knew the attack was going to happen. Reaction speed is reacting to an attack you don't know is going to happen or at a very close range. The reaction speed of a character also tends to be its highest speed.
The speed at which a thing crosses a certain distance, like going from the earth to the sun for example. High travel speed usually require similar reaction speed. People usually have lower travel speed than for other types of movement.
You can use this calculator to convert from one speed unit to another.
Subsonic (Faster than Eye) (Mach 0.1-0.5) (89-170 m/s or 200-500mph)
Sub-Sonic+ (Mach 0.5-0.9) (~300 m/s)
Transonic (Mach 0.9-1.1) (~340 m/s)
Supersonic (Mach 1.1-2.5)
Supersonic+ (Mach 2.5-5)
Hypersonic (Mach 5-10)
Hypersonic+ (Mach 10-25)
High Hypersonic (Mach 25-50)
High Hypersonic+ (Mach 50-100)
Massively Hypersonic (Mach 100-1000)
Massively Hypersonic+ (Mach 1000-8810.2)
Sub-Relativistic (1%-5% SoL)
Sub-Relativistic+ (5%-10% SoL)
Relativistic (10%-50% SoL)
Relativistic+ (50%-100% SoL)
Speed of Light
FTL (x1-10 Speed of Light)
FTL+ (x10-100 Speed of Light)
Massively FTL (x100-1000 Speed of Light)
Massively FTL+ (x1000+ Speed of Light)
Infinite Speed (As fast as desired)
Immeasurable (Higher-dimensional entities beyond linear time or 3D distance, and its' concepts of speed. Meaning: Level 2-C to 1-B.)
Irrelevant (Characters beyond the concepts of dimensions themselves. Meaning: Level 1-A and above.)
The speed tiers used have intersecting limits, and this may be confusing to some members. The divisions are made based on Exclusive Form grouping, in which the true lower limit is the given lower limit and the true upper limit is just short of the given upper limit.
1) Mach 10 is Hypersonic+, not Hypersonic.
2) Mach 100 is Massively Hypersonic, not High Hypersonic+.
Omnipresence must be specified in conjunction with the scale. Because omnipresence within a single 3+1-D universe (aka a regular 4-D space-time continuum) does not mean anything to regular life forms in higher dimensions of time and space (which might be larger and more complex than this universe).
Higher order dimensional nature does not guarantee immeasurable speed. Their Speed stat can be listed as "Immeasurable" only if there are higher temporal dimensions.