It means that events or actions will happen, one right after the other.
Backness is the quality or state of being a back vowel, relating to the position of the tongue when a vowel in a word is spoken.
The four parameters of vowel sounds are height, backness, tenseness, and rounding. Height refers to the position of the tongue in the mouth (high, mid, or low), backness refers to the position of the tongue in relation to the back of the mouth (front, central, or back), tenseness refers to the amount of muscle tension in the tongue (tense or lax), and rounding refers to the shape of the lips (rounded or unrounded).
A vowel diagram is a visual representation of vowel sounds in a particular language. It typically shows the positioning of vowels in relation to each other based on factors like tongue height, backness, and rounding. Vowel diagrams can help linguists study and analyze the vowel system of a language.