What this site is for
This is patient education about the skin, published by Chongqing West District Hospital, a tertiary general hospital in Jiulongpo District, Chongqing. It is an area guide rather than a device page: it answers which structure is producing a complaint, which options reach that structure, and how to choose between them. The individual treatments are described on the guides this site links to, and repeating them here would help nobody.
The distinction the site is built on
The barrier, the pigment cells, the collagen and elastin scaffold, the vessels and the oil glands produce almost every skin complaint, and they are changed by means that have nothing in common. A cream that repairs a barrier does nothing to a vessel; light absorbed by pigment leaves the scaffold untouched; needling that builds collagen removes no mark. Most people arrive with all of this merged into one sentence, and naming the right structure is most of the decision.
What it deliberately does not do
It does not name products or brands, quote prices or dosages, or promise a result. It does not present a cream, a supplement or a device as a way of removing a scar or replacing lost skin, because none of them does either. It does not describe settings or technique in detail, and it does not tell you which option to choose: that follows from an examination, and a website cannot perform one.
The limits of a website
Nothing here can tell you which structure is producing your own mark, whether your skin will tolerate a course, whether a lesion is benign, or how much of a result is realistic for your skin type and history. Those answers come from someone examining you in good light and asking about your history, which takes minutes in person and cannot be taken from a photograph. Use this site to arrive at an assessment with better questions, and treat anything you read here as general information rather than as advice about you.