PDF opens the PDF. Available Online goes to full vendor record.
Just as you have an identity number for the government or for work, having a unique, personal identifier for your publications is very important.
ORCID allows the world to know that this publication is yours and not any of the other David/Yael Cohens. Today many journals and grants insist that you have an ORCID. It takes a few minutes to register at https://orcid.org/register. If you need any assistance contact your librarian at firstname.lastname@example.org.
Did you know that if you customize your google scholar settings you can link directly from the results list to the full text of the article or ebook? Go to scholar settings by selecting the settings icon on the upper right side of the screen. Now go to Library Links and search for Weizmann Institute of Science. Check the entry that reads "Weizmann Institute of Science - Find it @ WIS.
Now, after performing a search, the Find It@WIS icon will display next to the results - selecting this icon will allow you to link to the full text version of the article if it is available - that is, if Weizmann has a subscription to it.