In an IP rating the first number represents the resistance of the item to solids and the second figure indicates its resistance to liquids.
For example, if a camera has an IP rating of IP67,
6 = totally protected against dust and
7 = protected against effects of water immersion between 15cm-1m
IP ratings (International Protection Marking) is a national standard set by the International Electrotechnical Commission to give guidance as the the amount of protection a casing provides against external elements, such as water and dust. It aims to give consumers more specific information than simply ‘waterproof’ or ‘weatherproof’. Outlined in IEC 60529 (Degrees of Protection Provided by Enclosures – IP Code)