I am not an expert/dermatologist/skin care specialist, but this is based from my own knowledge from years of research regarding skin care. I hope this could help with your confusion. Feel free to correct me if ever you feel like or think that some of the things I wrote are incorrect.

For daily use :
• Make-up removers - removes makeup, used before facial washes.
>They have different kinds : cream, oil, or water types. There are also make up remover wipes.
• Facial Washes/Cleansers (depends on how you wanna call it, it's the same.) - Cleans the make up, dirt, oils, etc. off of your face.
> Usually comes in gel, cream, foam, milk types.
• Toners - Removes excess dirt that the facial wash/cleanser wasn't able to remove. Also helps to balance out the pH level of the skin. pH level is the acidity level of the skin.
> Toners are typically witch hazel or water-based and contain minimal or no alcohol.
• Astringents - This is similar to toners except alcohol is the main component. The alcohol content in astringent makes it drying to the skin, which is beneficial for anyone with oily skin. The alcohol actually penetrates the excessive oil and helps normalize your complexion.
• Facial Moisturizers - Acts as a protective barrier for your skin, keeping it hydrated and healthy. And prevents it from drying out.
• Facial Serums - The main reason you'd want to use a facial serum is to get added nutrients and moisture into deeper layers of your skin that a regular moisturizer is not able to reach.
If you're still young, you don't need this yet.• Eye Creams - They are specially formulated for the sensitive, thin skin around the eyes, and helps get rid of puffy eyes, dark circles, and sagging skin.
Again, if you're still young, this isn't necessary.For weekly use (1-2 times a week) :
• Exfoliators1.) Manual Exfoliators•Facial Scrubs - This contains abrasive ingredients(example : beads, brushes, etc.) to remove dry, dead skin cells and helps improve blood circulation. It also softens the skin and gives it a healthier glow.
> Example : St. Ives Apricot Scrub(beads), Clarisonic skin cleansing brush
2.) Chemical Exfoliators - Makes use of several types of chemicals in order to remove dead skin cells and other impurities.
> Example : Cure Natural Aqua Gel
• Facial Masks - There are different types of facial masks for different skin types/problems/conditions. (example : extra moisture for dry skin, deep cleansing for oily skin, etc.)
These are usually left on/applied on the skin and let it penetrate for a certain amount of time, then rinse. They provide added benefits for the skin.
> They come in mask, clay, gel, or cream forms.
Only when needed use :
• Spot treatments - These are medicated and more concentrated(it depends on what ingredient is used, the usual ones are salicylic acid and benzoyl peroxide.) It goes deep down in pores to kill the acne bacteria that cause pimples and helps stop new ones from forming.
> There types of spot treatments like acne spot treatments, dark spot treatments, etc.
It takes time(trial and error) and to find the right or
"hiyang" products for your skin. What works for other people might not work for you. And when trying out new products, make sure to atleast use it for 2 weeks to a month(or more) to see if it really works or not. Because sometimes, the skin reacts if there's a new product but will eventually adjust.