That's about it. A fillibuster has two meanings. One is the good old fashoined stand up and read the phone book till you pass out model (think Jimmy Stewart or Strom Thurmond). Once you have the floor its yours till you yield or can no longer stand at the podium.
The other is about the cloture vote. The Senate rules can allow any member to object to a bill being voted on. At that point it requires 60 votes to agree to vote on the bill in question. Its a good provision as the Senate was designed (with its longer terms and staggered elections) to be a buffer against populist nonsense like these gun bills.