The aspect of attribution in the context of the license used by Stack Exchange, CC BY-SA 4.0 - https://creativecommons.org/licenses/by-sa/4.0/
Use this tag if your question is about attribution in the context of the CC BY-SA license used on Stack Overflow.
The term is described in the official license as:
Attribution — You must give appropriate credit1, provide a link to the license, and indicate if changes2 were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license3 as the original.
If supplied, you must provide the name of the creator and attribution parties, a copyright notice, a license notice, a disclaimer notice, and a link to the material. CC licenses prior to 4.0 also require you to provide the title of the material if supplied, and may have other slight differences.
In 4.0, you must indicate if you modified the material and retain an indication of previous modifications. In 3.0 and earlier license versions, the indication of changes is only required if you create a derivative.
You may also use a license listed as compatible at https://creativecommons.org/compatiblelicenses
For a comprehensive overview of how licensing on SE works at present has how it changed over time see: Creative Commons Licensing UI and Data Updates
Make sure to check the following FAQ articles: