In fallout 3 there are robot humans named andriods who act similar to the synths in fallout 4. I do belive there the same since ther both created by the institute but are andriods and synths truely the same?
As most people have stated, synths and androids are the same thing. The usage of the two terms by Institute personnel is mentioned by Shaun in the terminals.
"The term android has been used interchangeably with synth for as long as the Institute has existed. And though some of our older residents may actually prefer android (Dr. Zimmer being a prime example), the term synth has always been more widely used. Today, our third generation creations are truly synthetic beings, so the designation synth seems more appropriate than ever. From here on in, I strongly prefer all official Institute records and correspondences use the term synth or synths. Let us remember our past, and appreciate the legacy of the android. But let us live for the future, and recognize the power of the synth."