I'm reading this:
De todas formas, es importante apuntar que el objeto de Session no es compartido entre distintos usuarios, ni siquiera entre distintas pestañas del navegador
... and, in my mind, I'm translating it to myself thus:
In any case, it's important to note that the purpose of Session is not to differentiate between users, not even between different "pestañas" of the browser.
"pestañas"? What's that, I say to myself. I feed it to google translate, and get, "eyelashes."
Was zum Teufel ist hier los?
Could it be "instance"? I guess that kind of makes sense - after all, you blink your eyelash[es] in an instant...