This item is to allow a USB OTG (USB On The GO) mini A connector to accept a standard A type cable and act as a host, like your PC. It does what it says on the tin.
This is a MINI A, not a MINI B adaptor, OTG has 5 pins but it depends if you want it to act like a host, in which case you need a MINI A adaptor like this or something similar, or you need it to act as a device because you are connecting it to a host in which case the MINI B is needed. Most printers and PCs will act as a host so for a camera you would need the MINI B connector. If however you have an advanced PDA and want to connect the camera to it then the PDA end will need the MINI A connector.
Don't forget that the newer MICRO A and MICRO B and connectors have been specified and are appearing on mobile phones now, with the MINI A and MINI B connectors being valid but "deprecated" as a legacy solution.
The general OTG receptacle can be MINI AB or MICRO AB which can take both the MINI A and MINI B or MICRO A and MICRO B connectors.
Also, there are a number of mystery connectors out there which have been designed to lock in customers by conforming somewhat to the USB shell but have room for more pins etc... These can be tricky and only the original manufacturer will be able to support you on these.
So in short USB connectors come in A and B variety each can be in the female or male form depending on what is needed and for each there is a STANDARD, MINI and MICRO size variant.
A cable can in theory have any one of the connector variants at each end, some are more usual and meaningful, some maybe ridiculous and completely non standard as the manufacturer may be trying to lock you into something non standard or hard to get. And then there are completely non standard connectors which "appear" to be somewhat USB like and for these you are on your own.