A poly file is somehow like a cutout of the area you need.
In this case you get a box from Israel including areas of Jordan, Syria and Egypt from Geofabrik and the poly file will define the area more accurate to Israel itself.
which tool would you reccomend to extract the data from the osm/pbf file (i can use windows but prefers linux)?
(a most simple sample would also be appreciated but not a must)
thanks for your help!
p.s A link for various osm files, including israel can be found here (previous link is now broken): http://download.geofabrik.de/