The Web of Science Journal Selection Process is described bellow!
Many factors are taken into account when evaluating journals for coverage ranging from the qualitative to the quantitative. These include the following:
Basic publishing standards
Editorial content
International focus
Citation Analysis
No one factor is considered in isolation, but by combination and interrelation of data, our editors are able to determine the journal's overall strengths and weaknesses...
This question has been repeated many times before, anyway, you will find more details about this topic in the attached link, where the source is (www.elsevier.com).
The Web of Science Journal Selection Process is described bellow!
Many factors are taken into account when evaluating journals for coverage ranging from the qualitative to the quantitative. These include the following:
Basic publishing standards
Editorial content
International focus
Citation Analysis
No one factor is considered in isolation, but by combination and interrelation of data, our editors are able to determine the journal's overall strengths and weaknesses...
As @Emad has stated, just follow the link and you will find more than hundred similar and related questions. Many fine answers and resources are available.
One of those questions is the next one: How can i add a journal in scopus/elsevier?