Although related to cryptography, they are not the same. Steganography’s intent is to hide the existence of the message, while cryptography scrambles a message so that it cannot be understood. Steganography is one of various data hiding techniques, which aims at transmitting a message on a channel where some other kind of information is already being transmitted. This distinguishes Steganography from covert channel techniques, which instead of trying to transmit data between two entities that were unconnected before.
The goal of Steganography is to hide messages inside other “harmless” messages in a way that does not allow any “enemy” to even detect that there is a second secret message present. The only missing information for the “enemy” is the short easily exchangeable random number sequence, the secret key, without the secret key, the “enemy” should not have the slightest chance of even becoming suspicious that on an observed communication channel, hidden communication might take place.
Modern steganography entered the world in 1985 with the advent of the personal computer being applied to classical steganography problems.  Development following that was slow, but has since taken off, going by the number of “stego” programs available: Over 800 digital steganography applications have been identified by the Steganography Analysis and Research Center.  Digital steganography techniques include: ? Concealing messages within the lowest bits of noisyimages or sound files. ?Concealing data within encrypted data or within random data.