Cè (from ci è) and ci sono correspond to the English there is and there are. They state the existence or presence of something or someone.
Cè tempo; non cè fretta. (There's time; there is no hurry.) Ci sono molti italiani a New York. (There are many Italians in New York.)
Cè and ci sono should not be confused with ecco (here is, here are; there is, there are), which is used when you point at or draw attention to something or someone (singular or plural).
Cè una parola difficile in questa frase. (There's a difficult word in this sentence.)
Cè and ci sono also express the idea of being in or being here/there.
Scusi, cè Maria? No, non cè. (Excuse me, is Maria in? No, she isnt.)