Your developer or designer may incorporate your logo and other branding elements into your design. However, if you're using a purchased theme—or one of the default Magento themes—you may want to add these items yourself.
In this section, we will review some of the ways in which you can affect the visual presentation of your store.
Using the Luma theme as an example, we will change the default Luma logo to the one we created for Acme Sportswear.
The size you need for your logo is determined by your theme. Some themes constrain the logo size when displayed. For the ideal logo purposes, you should consider the following:
Size your logo as close to the size of which it will appear on your site. If you upload a huge file, it may be reduced in dimensions for appearance, but your customers will still be downloading a very large file, which can degrade their experience.
PNG files work best for graphics, yielding sharp, defined edges and a full color palette...