Phone interviews are normally organized in two situations: when the recruiter is doing a quick pre-selection of a large number of candidates or is doing a more thorough selection of candidates who are located in a different city than the company headquarters to prevent unnecessary travelling from any of the two parts (recruiter or candidate).
In the first case the phone interview is normally short – just 10-15 minutes and the questions addressed have the purpose of quickly accepting or rejecting the candidate for the next step. This interview is never the last one. At least one face to face interview will follow. Questions addressed sometimes test skills that the candidate claims to have in order for the recruiter to avoid wasting time – questions may test a foreign language, IT, engineering or any other technical or business knowledge. Questions are clearly targeted to a certain area and if the candidate fails to reply they don’t get a second chance, at least not immediately.
In the second case the interview is longer – even up to one hour and the questions addressed range from technical skills to personality, experience, role plays and case studies. This interview is again never a final one. Unless the position is a virtual or remote one, no company will hire you without seeing you face to face. Not even a Skype interview is enough if you are working in an office. Expect them to wish to see you.
Coming back to the phone interview – depending on the position, sometimes two or more phone interviews may be used during the same recruitment phase. One may test for example language skills for 10 minutes and then if you pass another recruiter may test your technical skills. The two interviews are rarely during the same day; rarely, but not impossible.
To sum up, the phone interview is the type of interview where you are asked questions over the phone, it has the same value as a face to face interview, but very rarely expect it to be final. However, if you fail it, you will not be invited to the following step which is the face to face one.