The term frenulectomy / frenectomy refers to the re-positioning or removal of the frenulum. A frenum is an attachment between two tissues. There are frenums connecting the tongue to the floor of the mouth, connecting the tissue of the cheeks to the gums.
When these frenums are to short and close to the edge of the gum they can pull downwards on the gum, which contributes, to root exposure/recession of teeth.
If the frenum in your tongue is attached too close to its tip, it might limit the function of your tongue, which restricts proper enunciation of words.
In some individuals a strong frenum can separate the front teeth and if not removed, the space can relapse even after it was closed with braces / orthodontics.