As we already know that currently there are many abstract and citation databases, and mostly preferred are SCOPUS and WoS. So, my question is which we opt for publication of our research article and why?
My response will be similar to Witold Bogusz , because we work in similar legal environment (in Poland).
I'd like however underline one difference:
1. Scopus (Elsevier) is more uniform - all indexed papers (both journals and conferences) are gathered in one group and are evaluated the same way. Papers from highly rated journals appear in the same group with conference proceedings series that do not necessarily provide a quality reviewing process. So it is quite easy to "pump up" H-index with large number of citations from conference proceedings. In my opinion the metrics provided by Scopus are very creditable (fair) but not really helpful in evaluation of scientist’s impact. What I find very positive is the “creditability”. The sources are “indexed” or “not indexed” so the author knows before the publication.
2. Web of Science is composed from many databases, including journals evaluated in Journal Citation Reports (JCR) that provide so-called Impact Factor (IF) for journals, Core Collection collecting both: journals and conferences (from Conference Proceedings Citation Index) and many “regional” databases (Russian, Korean, Chinese) that can be considered separately or together (choosing “All databases” option). I appreciate very much the attempts to select only best contributions to be indexed in Core Collection. Some decisions of Clarivate Analytics are however strange, like e.g. choosing selected issues of journals or conference series for indexation. That brings some doubts about the criteria of this selection. Some CPCI conference organizers are notified about the negative decision after months or even years after publication.
1. If you publish a journal paper: look for JCR journals (the indexation in Scopus will be granted anyway as the large majority of JCR journals appear also in Scopus).
2. If you publish a conference paper, check if the proceedings will be indexed in Scopus, the information about indexation in Web of Science does not guarantee anything as all the conference proceedings are evaluated individually after delivery to Clarivate Analytics. And the criteria of this evaluation are not really clear.
Scopus claims to be the largest abstract and citation database of research literature and quality web sources. This claim has been challenged (Jacso, 2011).
Scopus contains 47 million records, 70% with abstracts
Over 19,500 titles from 5,000 publishers worldwide
Includes over 4.9 million conference proceedings, 1,200 Open Access journals
Scopus provides 100% Medline coverage
20+ million records back to 1996 with references
20+ million pre-1996 records go back as far as 1869
Results from 386 million scientific web pages
22 million patent records from 5 patent offices
Seamless links to full-text articles and other library resources
Innovative tools that review search results and refine to most relevant hits
Alerts to keep you up-to-date on new articles matching your search query, or by favorite author
Scopus covers 250 million quality web sources, including 22 million patents. Searches in Scopus incorporate searches of scientific web pages through Scirus, and include author homepages, university sites and resources such as preprint servers and OAI compliant resources.
Web of Science is updated with approximately 25,000 articles and 700,000 cited references added each week.
Covers 12,311+ journals from 256 categories, 110,000 proceedings from conferences, symposia, seminars, colloquia worldwide
Journal backfiles to 1900, cover-to-cover indexing, cited reference and chemical structure searches
Science – 7100 international journals and highly cited book series in 170 categories back to 1900
Social Sciences – 1,750 international journals and highly cited book series in 50 subject categories back to 1954
Arts & Humanities – 1,200 international journals and highly cited book series in 25 categories back to 1975
Complete backfiles to 1945 however put total at ~37 million records
Cited reference and chemical structure searches
Author identification tools
Analysis capabilities
Direct links to your full-text collections
Index Chemicus®: Over 2.6 million compounds, to 1993
Current Chemical Reactions®: Over one million reactions, to 1986, plus INPI archives from 1840 to 1985.
WoS provides unique search methods and cited searching. Users can navigate forward and backward through the literature, and search all disciplines and time periods. Users can navigate to print and electronic collections using institutional linkresolvers.
Web of Science (WoS) is searchable with complete bibliographic data, cited reference data and navigation and links to full text.
Scopus is the largest abstract and citation database of peer-reviewed literature, with bibliometrics tools to track, analyze and visualize research. It contains over 22,000 titles from more than 5,000 publishers around the world, covering the fields of science, technology, medicine, social sciences, and Arts & Humanities. Scopus has 55 million records dating back to 1823, 84% of these contain references dating from 1996.
I suggest you follow https://www.scimagojr.com/journalrank.php?category=2601 and https://www.scopusjournals.info/2019/04/mathematics-journals-indexed-in-scopus-2.html