Uniform circular motion has the same speed but not velocity. Why?
Speed just tells you what your speedometer would read. Velocity is a combination of speed AND direction. In the case of circular motion, this difference becomes important. While traveling in a circle, you are constantly changing your direction. A change in direction changes your velocity and by definition requires an acceleration.
Some circular anatomy:
Period: The amount of time it takes to make one rotation.
The symbol for period is T (how much Time it takes for one cycle). The "T" is capital and often looks rather angry.
Frequency is how often it circulates per second (minute…)
The symbol for frequency is f. It's a cool graceful italic/script "f".
The units for frequency is cycles per second or 1/sec also called Hertz (Hz):

“The drill is circulating at 60 cycles per second.”

“The drill is circulating at 60Hz.”

“The drill has a frequency of 60 cycles per second.”

“The drill has a frequency of 60Hz.”
all mean the same thing.
The unit 1/sec is a rather strange unit (it’s up there with s^{2}. Really? How can you square a second?) It makes it a little easier to wrap your head around it if you read it as “per second” instead of “1 over seconds”
As the time for a cycle increases, the frequency will decrease. If you take a longer time for each cycle, you will get less cycles.
As time gets smaller, frequency gets bigger.
Frequency and Period are inverses of each other.
T = ^{1}/_{f} and f = 1/_{T}
Circular velocity = ^{2 πr}/_{T}
(v = ^{d}/_{t} so in a circle, the distance you travel is 2 πr and divide it by the time T) 