Big difference, Synthetic, generally refers to the thing itself being Synthetic, rather then Natural, whereas Man Made, refers to the process. Just because something is Man Made, does not by necessity make it Synthetic, look at all the man made mistakes in life, you wouldn't call them Synthetic Mistakes, would ya? or what about Man Made automobiles, you would call them Synthetic Transportation Vehicles would you? I mean,, cup cakes are man made, but are they Synthetic?
It is man made
Yes, they are man-made.
wood made by man!
it is man made
Some rivers are man made
Unnatural and Man-made
Something not man-made is typically referred to as natural, such as trees, rivers, mountains, or animals.
man made
It is synthetic
man made structures are something that a human builds, and a natural structure is something that comes into the world naturally.
Man made resources is meant by which is artificially affected and made by man.
Natural.
Synthetic.
If something is not man-made, it is typically considered to be natural, meaning it occurs in nature without human intervention or influence.
Something which is man-made, such as buildings and statues - not rocks and trees.
Man-made is something the humans have made like plastic or paper, and so on! Natural Resources is wood and water and so on.