It's a subtle difference, but there is a difference.
In the synastry, everything said above is true, and in this type of chart one person relates to the other.
In the composite, it reflects a general quality of the relationship between the two persons, not the individual energies of the two.
So in the relationship itself, there will be emotional stability, coldness, commitment between the two. With nuances depending on the other aspects in the chart.
Because it is a composite, it can be the result of different aspects in the synastry. There could be, for example, squares between the Saturns and trines between the Venuses, with the two midpoints at the same point, creating a Venus/saturn conjunction in the composite.
As another example, mahaira you have a Saturn/venus conjunction in the synastry. How does the composite work out between you and your husband?