It is true that concealers and foundation does the same job of concealing the ugly marks that one wants to hide. But there has to be a reason why they are made into two separate products. It’s common to use a foundation to hide the blemishes, but that is not the primary function of a foundation. A foundation is used to even out the skin tone, in case it’s not. For all extroverts out there, it is quite common to have a varied skin tone, even on the face. So, a foundation, as its name suggests, puts a firm base to your makeup along with making your skin tone look even. A concealer is something that, as its name suggests, primarily used as a liquid to conceal the blemishes and scars. So why go for a concealer if the foundation does the job? Well, there is really no need to use a concealer if the foundation you use has done the job of concealing your marks and blemishes. But if it does not, you can use concealers to fix them. Remember that a concealer is used only on a specific area that you want to hide, like dark circles, zits, pimples and other little scars on your skin. Concealers usually come in liquids that you need to squirt out a little and dab them on the scar or blemish that you want to hide. This is usually worn over the foundation. But if you are not going for an elaborate makeup and only want to hide your blemish, you can skip the foundation and go for a concealer. Since this is their primary job, unlike the foundation, they do a better job at concealing the marks. A concealer always comes in the form of liquid that is considerably thicker than the liquid foundation. This helps in covering the marks more efficiently compared to foundation. But a concealer cannot be used to even out the skin tone since the thick liquid ends up giving a strange appearance. A foundation might do a double job, but if you need a quick fix, a concealer would be the best option. Source: gracenglamour.com