Eyelash extensions involve attaching individual synthetic or mink lashes directly to each of your natural eyelashes one by one. This creates a more seamless and natural look as the extensions follow the natural growth pattern of your lashes. The process usually takes longer and requires more skill and precision.
Lash clusters, on the other hand, are small groups of lashes that are applied to your natural lashes in sections. They can give a more voluminous effect but might not look as seamless as individual extensions. Lash clusters are often easier and quicker to apply for those who prefer a DIY approach or for temporary occasions.
The choice between the two depends on your desired look, the occasion, your skill level if applying them yourself, and your budget.