The only thing they have in common is that they are made from pork.
'Salame' is a long cylinder that can be sliced, and, as an instance, the slices can be used to make tasty sandwiches, and MUST NOT be cooked.
There are many different types of 'salame' like 'salame Milano', 'salame Ungherese', 'salame piccante'
or 'soppressata Calabra'. The main ingredient is seasoned pork meat.
'Sausage' is soft and raw meat, that MUST be cooked also for health reasons, and usually
is served with vegs, as an instance, in Italy you can have 'sausages and broccoletti',
also said 'sausages and friarelli', which is very, very good.
Both 'salame' and 'salsiccia' contain a high percentage of animal fat.
let me suggest to you to visit 'google images' and to make these two queries:
a) Panino al salame
b) Salsiccia e friarelli.
Warning: absolutely don't do that if you are feeling hungry and the fridge is empty.