It's not a daft question, i'll try to explain it. Here goes.
R in the R1, R2 etc actually means "region".
Now the 0, 1, 2 etc refers to the actual region that dvd is from.
For a list of what region, is what number just see below.
Region code Area
0 Informal term meaning "worldwide". Region 0 is not an official setting; discs that bear the region 0 symbol either have no flag set or have region 1–6 flags set.
1 Bermuda, Canada, United States and U.S. territories
2 European Union, Albania, Andorra, Armenia, Bahrain, Bosnia and Herzegovina, Croatia, Denmark, Egypt, Faroe Islands, French overseas territories, Georgia, Greenland, Guernsey, Iceland, Iran, Iraq, Isle of Man, Israel, Japan, Jersey, Jordan, Kuwait, Lebanon, Lesotho, Liechtenstein, Macedonia, Moldova, Monaco, Montenegro, Norway, Oman, Qatar, San Marino, Saudi Arabia, Serbia, South Africa,Sweden, Swaziland, Switzerland, Syria, Turkey, United Arab Emirates, Vatican City State, Yemen
3 Southeast Asia, Hong Kong, Macau, South Korea, Taiwan
4 Australia, New Zealand, Caribbean, Central America, Oceania, Jamaica (except French Guiana), Mexico, South America
5 African countries not explicitly included in other regions, Indian subcontinent, countries included in the former Soviet Union, Mongolia, North Korea
6 People's Republic of China (exclude Macau, Taiwan)
7 Reserved for future use (found in use on protected screener copies of MPAA-related DVDs and "media copies" of pre-releases in Asia)
8 International venues such as aircraft, cruise ships, etc.
ALL Region ALL discs have all 8 flags set, allowing the disc to be played in any locale on any player.
9 Is a region number on some dvd players, that will enable you to play any region discs on your dvd player. (which makes them mutli region, which i do have some codes for).
I hope this has answered you question for you.