An arithmetic progression is a set of numbers where the difference between the two consecutive numbers is the same. This means that we keep adding or subtracting a fixed number from a value to form an arithmetic progression (or AP).

Eg- The set of numbers \(\{10,14,18,22,...\}\) is an AP as the difference between consecutive terms is \(4\). You can also explain this by stating that starting from 10, we keep adding \(4\) to the subsequent numbers to get our sequence.

Now that we can identify APs, let's take a look at some common terminologies for an AP.

1. First Term - As the name suggests, this is the first term of the sequence. For the AP \(\{2,4,6,8,10,...\}\), \(2\) is the first term. This is usually denoted by \(a\). It helps us identify the other terms of the AP. 
2. Common Difference - The fixed number that we add or subtract to a value to form an AP is the common difference. It can also be computed by subtracting two consequent terms. For the AP \(\{2,4,6,8,10,...\}\), \(2\) is also the common difference as \(4-2=6-4=8-6=10-8=2\). This is usually denoted by \(d\).
3. General Term - An algebraic expression can be used to express the \(n^\text{th}\) term of an AP. Consider an AP with first term \(a\) and common difference \(d\). Then the AP would look something like this \(\{a,a+d,a+2d,a+3d,...\}\) as we keep adding the common difference \(d\) to the first term \(a\). Thus, the \(n^\text{th}\) term of the AP can be written as \(a_n=a+(n-1)d\) where \(a\) is the first term and \(d\) is the common difference.