The IPA describes vowels by the position (height and backness) of the tongue in the mouth and the rounding of the lips. Here is the chart it uses to describe vowels, and each vowel’s symbol.
The IPA maps hundreds of consonants on several different charts; including consonants that are pulmonic (all English consonants), clicks, ejectives, and more. The chart maps each sounding, describing how it is made. It describes its place of articulation in the mouth, manner of articulation, and voicing. Here is the English IPA consonant chart:
As you can see, some of these symbols look similar to English letters, but some look very different.
For comparison, here is a picture of the Spanish IPA consonant chart. It also only consists of pulmonic sounds, and has many similarities to that of English. However, you should notice some different sounds.
