These addresses are 32 bit numbers, normally written as four decimal numbers, one for each 8 bits of the address. This is called dotted-decimal notation. A Note about addresses. It is usually a good idea to use hostnames instead of IPs whenever possible, so that if the machines are changed around, the names can still point to the proper machines. It can include the entire alphabet, upper and lower case, the digits, and all the symbols on the keyboard.
Binary files are files that include more characters than just text.
Most mailers or news readers can not send or receive binary files. The first parameter is the files you want to encode, the second is the file you want to call it when it is uudecoded. Usually, the second parameter will be the same as the first. This traps it to a file. When all finsihed, the file.uue will contain the uuencoded file.