Is aspect ratio the same as pixels?

No, there is a difference between pixels and aspect ratio. A website or app might ask you for a certain pixel size (e.g., 400 x 400), which would be a 1:1 aspect ratio. But 800 x 800 pixels is also 1:1.

Whenever you upload something to social media or send it for printing or publishing on the web, it is important to pay attention to aspect ratio requirements and pixel size.

Using the right aspect ratio will make sure your image fits the shape of the available space, and using the right pixel size will make sure your image has enough detail but isn’t so large that it slows down the loading time for the page (very bad for search engine rankings).