Meaning of "se" in following phrase?

Question

"se necesita esto para viajar a diferentes paises":
This phrase describes the function oa a passport, but I don't know 2 things: (1) What is meaning of "se" here? (2) could the phrase used "este" just as well as "esto"?

Answer 1

(1)Se has many uses and in this case, is used to modify the verb necesitar. This is an example of "impersonal se". When impersonal se is used, the subject of the verb (which is normally stated) is left unspecified. Without a subject, this gives a general statement.

Habla español aquí = He/she/you (formal) speak Spanish here

Se habla español aquí = One speaks Spanish here/Spanish is spoken here

(2)I answered your other post which addresses this question

Answer 2

I could be wrong, but I believe "se" is used when speaking in general terms. In general, a passport in necessary to travel to different countries.

Answer 3

Look at this website.

http://www.indiana.edu/~call/reglas/pron_se.html

Hope it helps!!!!