ECHs - ear canal headphones
These earphones are very small and inserted slightly into the ear canal. They provide the very best seal from outside sound of any headphone design. Ear canal headphones seal within your ear canal utilizing little silicone/ear gels tips, coating your eardrum with precisely-rendered music. The audio image from ear canal headphones is more compact and more "inside your head" than regular headphones/ the sound from this type of headphones is truly crystal clear.
Ear bud headphones
They are handy, unobtrusive and with consumer friendly price.Ear buds don't provide full ambient noise-attenuation like ECHs. They are for listeners tired of the deeply invasive in-ear canal headphones design.