BinaryWrite

BinaryWrite[channel,b] writes a byte of data, specified as an integer from 0 to 255. 

BinaryWrite[channel,{b1,b2,…}] writes a sequence of bytes. 

BinaryWrite[channel,"string"] writes the raw sequence of characters in a string. 

BinaryWrite[channel,ByteArray[…]] writes the contents of a ByteArray object.

BinaryWrite[channel,x,type] writes an object of the specified type. 

BinaryWrite[channel,{x1,x2,…},type] writes a sequence of objects of the specified type. 

BinaryWrite[channel,{x1,x2,…},{type1,type2,…}] writes a sequence of objects with a sequence of types. 

Please visit the official Wolfram Language Reference for more details and examples on core symbols.