:salamext: brother,
Some acts of worship, like prayer, can be divided into pillars (arkaan), obligatory parts (wajibaat) and recommended (sunan). For a detailed breakdown of what each of these mean and which parts of the prayer belong in which category, you can read this link (but be aware that there may be some variation depending on which maddhab you follow):
http://islamqa.info/en/65847
Reciting al-Fatihah falls in the category of a pillar - it cannot be missed out. However, for prayers where the Imam recites out loud, scholars differed as to whether the people behind him need to recite it. There is some discussion about this here:
http://islamqa.info/en/10995
And Allaah :swt: knows best.