what is the meaning of && in PostgreSQL?

Question

In PostGIS, what is the result of the && operation between two geometries? In my mind, && returns a boolean, but does return geometry this time. In the following example, the operation is between a LineString and a Polygon.

Firstly, I guess this is the relationship between inclusion and being included. Until I do the following example, I think this should be a relationship of type "intersection". Am I right?

select ST_geomfromtext('linestring(0.1 0.1,1.9 1.9)', 4326) && st_geomfromtext('POLYGON((0 0,0 1,1 1,1 0,0 0))', 4326)

The result is t which represents true.

Answer 1

It's an intersection operator &&

boolean &&( geometry A , geometry B );

boolean &&( geography A , geography B );

The && operator returns TRUE if the 2D bounding box of geometry A intersects the 2D bounding box of geometry B.

How one could find it using google:

1. Search for "postgis operators"
2. On the first page https://postgis.net/docs/reference.html search for &&