The purple blob ?? can't tell....
Earbuds sit just inside the shell of your ear
are meant to be inserted and for a proper fit you get different sizes and shape of tips...like these from Westone so they fit deep into your ear canal and attentuate sound just as earplugs do
Headphones go over the top of your head or behind your neck.
The fit of the tip on earphones is critical to both the sound quality, the sound attentuation and staying in tho I use a thin Oxford balaclava as it keeps them in place well and much easier to get helmet on and off.
The Shures and others go into your ear canal and tuck into the shell of your ear.
The fit in your ear canal depends on the tip - riders should be using acoustic foam tips the correct size from Westone or Comply. Unfortunately even the Westone wear out so need to be replaced from time to time but getting the correct fit is vital.
Etymotic really sort of started the sealed ear canal design
Etymotic Research | Earphones
I've not liked them compared to others like UltimateEars.....
Some of these earphones are north of a thousand dollars even up to $4k+ designed for musicians or off the deep end audiophiles.
I like the sound of the UEs but not as durable as the Shure.
Unfortunately the language of earbuds, earphones, in ear monitors, in ear headphones keeps everyone confused.
Bottom line for good sound you need a good seal.
Riders need an earphone that stays in and attentuates the external sounds and is durable. Shure 215s hits all the buttons when you use the acoustic foam tips.