The license for individual CAD symbols and footprints allows you use them in commercial and non-commercial manufactured designs without attribution or other license restrictions (details below).
Individual CAD symbols and footprints on SnapEDA are licensed with a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA) with the Design Exception 1.0. This license allows designers to use CAD files downloaded from SnapEDA for commercial and personal use free of charge, and make derivative works. If CAD files, or derivatives thereof, are shared publicly, attribution must be given to the source (SnapEDA and the original author, as applicable), as outlined by the requirements of the license.
Use of the SnapEDA website is governed by the Web Site Terms and Conditions of Use.
In short, you cannot use the SnapEDA website for the purpose of sharing the content on the Internet or within an EDA tool, but otherwise you are free to use the files for designs.