Gel is the material that strengthens the nails.

The capsule is a technique for a nail extension using a plastic capsule that is stuck to the end of the nail (the gel serves as glue for me because it is obviously more suitable, resistant and healthy on the natural nail, than a capsule glue containing cyanoacrylate which also does not necessarily adhere to the natural nail plate and which says poor adhesion = poor hold).
The capsule is a technique suitable for all types of nails.

The stencil is also a slightly more complex extension technique to create a nail extension, it is a paper support that is placed under the natural nail and we then create the extension using the gel or acrygel, this technique must be mastered for perfect installation because the gel extension is completely created by the professional. This technique is not suitable for all types of nails.

The terms used above are techniques so depending on the extension technique chosen by the professional in capsule or stencil the final rendering will be the same. I often hear customers say that the capsules are thicker and vice versa with the stencil that one or the other looks more natural, but this has absolutely nothing to do with the extension technique but on the other hand it can make Thick is the material placed on it subsequently, i.e. resin gel or acrygel, to have a fine and natural result you need to know how to work these materials finely and have perfect filing.
You will never have thick results with me I like to work with gel nails for a thin and natural result and it remains just as solid. After all, this is what we are looking for for natural results and durable, strong nails!

The fillings must be carried out between 3 to 4 weeks, it all depends on your nail regrowth more or less quickly, it is on a case by case basis ^^, they should not wait too long in order to avoid accidents of breakage and weakening your nails, this is why maintenance between 3 and 4 weeks is generally recommended.