The Western Mediterranean and its lands.
Both wanted to control of the land and both had the resources and desire to fight.
When Carthage and Rome were allies, Carthage was a sea power, Rome a land power. Rome had to organise a fleet when war broke out with Carthage.
because romans wanted to have more land then them.
It was three wars over 120 years for control of the Western Mediterranean.
The punic Wars were a contest between Rome and Carthage for control of the Western Mediterranean. When Rome destroyed Carthage it achieved that goal, and in then taking retribution against Macedonia for supporting Carthage, launched itself into the Eastern Mediterranean.
Carthage.
Rome fought in the Punic Wars, which began late in the 3rd century B.C.E. and ended in the middle of the 2nd, as a result of several factors. The first was economic, as control of the central Mediterranean was of critical importance for successful Roman trade. The second was more strictly military and political: as an aggressive, expansion-minded civilization, Rome sought to become dominant among its neighbors, especially Carthage, its primary opponent in the Punic Wars.
Carthage was bent on extending its influence and trade in Sicily. Rome had established control of the Italian peninsula. They were allies of convenience as Roman land power and Carthagenian sea power were complementary. Sicilian cities threatened by Carthage appealed to Rome, and Rome, seeing an opportunity, sided with them, provoking war.
They were originally allies in controlling Greek penetration in the Western Mediterranean with complementary forces - Rome on land, Carthage on the sea. They came into conflict as Rome, having dominated Italy, sought to extend into Sicily, clashing with Carthage's foothold on the Island. This brought on the First Punic War; their second and third wars were a struggle for control of the Western Mediterranean.
The Roman Republic and the Carthaginian Empire were looking for land, when there army's collided and fought to the death for the land Sicily.
Carthage had several advantages at the beginning of its first war with Rome. Very importantly Carthage had a developed navy. This enabled their military to embark to what it deemed strategic places in the Mediterranean Sea. Another advantage Carthage had was control of strategic islands in the Mediterranean, namely Sardinia and Corsica. Carthage had Greek allies in Sicily, the south of the Italian peninsula, and as faraway as Corinth. Carthage had a long standing position in Western Spain as well. For the most part she was in control of shipping and land bases in the western Mediterranean Sea.
There were three Punic Wars and each of them had different causes. The First Punic war was precipitated by some mercenaries from southern Italy who seized the city of Messana (modern Messina) on the east coast of Sicily. They were attacked by the Greek city of Syracuse, the most powerful city in the island (there were Greek cities in the east and the south of Sicily). Carthage had five ports in the west of Sicily. In the past there had been wars between the Carthaginians and the Greeks of Sicily. The mercenaries asked both Rome and Carthage for help. The former decided to help, but established a garrison in Messana. Not happy with this the mercenaries asked Rome for help again. Rome expelled the Carthaginian garrison from Messana and then besieged Syracuse which was forced to become an ally of Rome. Concerned about this alliance, Carthage mobilised for war. In Second Punic War Hannibal, the Carthaginian general, wanted war because he wanted revenge against Rome for fraudulently seizing Corsica and Sardinia from Carthage taking advantage of the fact that the latter was facing a military rebellion after the first war. Hannibal provoked the war and quickly mobilised an army to invade Italy from his base in the Carthaginian territories in southern Spain. Rome used an excuse to declare war for the Third Punic War. A political faction in Rome wanted to destroy Carthage because she had recovered economically from the second war. They were afraid of a resurgence in the power of their rival and wanted to eliminate it.