Hypocrisy is the insincerity of a person by virtue of pretending to have qualities or beliefs that one does not really have or Hypocrisy means showing a good face whilst concealing bad intentions, and harbouring ill will whilst appearing good in order to cause harm.
Munafiq (plural munafiqun) is an Arabic term, Islamically it is used to describe a religious hypocrite, who outwardly practices Islam, while inwardly concealing his disbelief (kufr), perhaps even unknowingly.
"Munafiq" is a person or a human who shows Eeman and hides Kufr (disbelief). He was given this name because his action is like the one of the Jerboa, which enters its burrow from a direction and gets out from another one. So he is a Munafiq who has entered Islam through a door in one direction and has got out from Islam through another door in another direction. This word “Munafiq” was not known before Islam. The Arabs did not know it in its specific meaning i.e. the one who hides his kufr and shows his Eeman.
Therefore Nifaq (Hypocrisy) is the character of a person having this quality and Munafiq (Hypocrite) is the person itself who is having the quality of Nifaq. 
The hypocrites are always confused, always planning deceit and plots. Although outwardly they appear to be with the believers, inwardly they are with the kaafireen (disbelievers of Islam). So sometimes they are inclined towards the believers and sometimes they are inclined towards the kaafireen.
“(They are) swaying between this and that, belonging neither to these nor to those; and he whom Allah sends astray, you will not find for him a way (to the truth — Islam)” Qur’an.Surah Nisa 4:143
Because of the corruption of their hearts, the hypocrites are the most aayath of mankind to the religion of Allah (Glory be to Him), as Allah tells us about them (interpretation of the meaning): “And when it is said to them: ‘Come to what Allah has sent down and to the Messenger (Muhammad),’ you (Muhammad) see the hypocrites turn away from you (Muhammad) with aversion” Qur’an.Surah Nisa 4:61
The dealings of the hypocrites revolve around their own interests. When they meet the believers, they make a show of belief and loyalty, in order to deceive the believers and as an action of dissimulation, hoping for whatever good and war-booty they have. But when they meet their masters and chiefs, they say, we are with you in your shirk and kufr. Allah (Glory be to Him) says concerning them (interpretation of the meaning): “And when they meet those who believe, they say: “We believe,” but when they are alone with their Shayaateen (devils — polytheists, hypocrites), they say: “Truly, we are with you; verily, we were but mocking Allah (Glory be to Him) mocks at them and gives them increase in their wrong-doing to wander blindly” Qur’an.Surah Baqarah 2:14-15 
Types of Hypocrisy
There are two categories of hypocrisy:
1. Hypocrisy in Belief.
2. Hypocrisy in deeds and actions.
1. The hypocrisy in Belief
Hypocrisy in Belief is of six types
2. Denial of the thing with which the Messenger is sent.
5. Rejoicing at the disgrace of Islam.
6. Disliking the prevalence of Islam.
Any one of the [above six types] is major Nifaq [Hypocrisy]– disbelief outside of the religion
2. Hypocrisy in deeds and actions
The hypocrisy in deeds and actions is of five types:
1. When he speaks, he lies.
2. When he promises, he breaks it.
3. When he is entrusted, he betrays.
4. When he disputes, he acts immorally.
5. When he makes a contract, he makes acts disloyally.
Hypocrisy from Noble Qur’an by Dr.Muhsin Khan
The hypocrites have many characteristics, the worst and most serious of which is disbelief in Allah (Glory be to Him). Allah says (interpretation of the meaning): “And when it is said to them (hypocrites): ‘Believe as the people (followers of Muhammad (May Allah honour Him and grant Him peace), Al-Ansaar and Al-Muhaajiroon) have believed,’ they say: ‘Shall we believe as the fools have believed?’ Verily, they are the fools, but they know not” Qur’an.Surah Baqarah 2:13
Among their characteristics are enmity and envy (hasad) towards the believers, as Allah says (interpretation of the meaning): “If good befalls you (O Muhammad), it grieves them, but if a calamity overtakes you, they say: ‘We took our precaution beforehand’ and they turn away rejoicing” Qur’an Surah 9:50
Among their characteristics is mockery of Allah (Glory be to Him), His Messenger (May Allah honour Him and Grant Him peace) and His religion. Allah (Glory be to Him) says (interpretation of the meaning): “If you ask them (about this), they declare: ‘We were only talking idly and joking.’ Say: ‘Was it at Allah, and His Ayaat (proofs, evidences, ayaths, lessons, signs, revelations, etc.) and His Messenger that you were mocking?’ Make no excuse; you disbelieved after you had believed” Qur’an.Surah Tawbah 9:65-66
Among their characteristics is that they spread corruption on earth, with disbelief, hypocrisy and sins. Allah (Glory be to Him) says (interpretation of the meaning): “And when it is said to them: ‘Make not mischief on the earth,’ they say: ‘We are only peacemakers.’ Verily, they are the ones who make mischief, but they perceive not” Qur’an.Surah Baqarah 2:11-12
Among their characteristics are slander and lies. Allah (Glory be to Him) tells us about them (interpretation of the meaning): “They swear by Allah that they are truly, of you while they are not of you, but they are a people (hypocrites) who are afraid (that you may kill them)” Qur’an.Surah Tawbah 9:56
Among their characteristics is that they enjoin what is evil and forbid what is good, and they are stingy with their wealth. Allah (Glory be to Him) says concerning them (interpretation of the meaning): “The hypocrites, men and women, are one from another; they enjoin (on the people) Al-Munkar (i.e. disbelief and polytheism of all kinds and all that Islam has forbidden), and forbid (people) from Al-Ma‘roof (i.e. Islamic Monotheism and all that Islam orders one to do), and they close their hands [from giving (spending in Allah’s Cause) alms]. They have forgotten Allah, so He has forgotten them. Verily, the hypocrites are the Faasiqoon (rebellious, disobedient to Allah)” Qur’an.Surah Tawbah 9:67
Among their characteristics are greed and avarice: “And of them are some who accuse you (O Muhammad (May Allah honour Him and grant Him peace)) in the matter of (the distribution of) the alms. If they are given part thereof, they are pleased, but if they are not given thereof, behold! They are enraged! Qur’an.Surah Tawbah 9:58
Among their characteristics are those which were described by the Messenger (May Allah honour Him and Grant Him peace): Narrated 'Abdullah bin 'Amr®: Messenger (May Allah honour Him and Grant Him peace) said, "Whoever has the following four (characteristics) will be a pure hypocrite and whoever has one of the following four characteristics will have one characteristic of hypocrisy unless and until he gives it up.
1. Whenever he is entrusted, he betrays.
2. Whenever he speaks, he tells a lie.
3. Whenever he makes a covenant, he proves treacherous.
4. Whenever he quarrels, he behaves in a very imprudent, evil and insulting manner."
Sahih Al Bukahari Vol 1:33 and Sahih Al Muslim Vol 1: 111. 
Among their characteristics is a concern with appearances and fancy speech whilst they are inwardly corrupt. Allah (Glory be to Him) says concerning them (interpretation of the meaning): “And when you look at them, their bodies please you; and when they speak, you listen to their words. They are as blocks of wood propped up. They think that every cry is against them. They are the enemies, so beware of them. May Allah curse them! How are they denying (or deviating from) the Right Path?” Qur’an.Surah Munafiqun 63:4 
Allah (Glory be to Him) has decreed that the ultimate destiny of the kuffaar and hypocrites will be in Hell: “Surely, Allah will collect the hypocrites and disbelievers all together in Hell” Qur’an.Surah Nisa 4:140
Hypocrisy is a serious sickness and a great crime. It means making an outward display of Islam whilst inwardly concealing kufr. Hypocrisy is more dangerous than kufr (disbelief) and the punishment for it is more severe, because it is kufr mixed with Islam and its harmful effects are greater. Hence Allah (Glory be to Him) will put the hypocrites in the lowest level of Hell, as He says (interpretation of the meaning): “Verily, the hypocrites will be in the lowest depth (grade) of the Fire; no helper will you find for them “ Qur’an.Surah Nisa4:145. 
Narrated Abdullah ibn Mas’ud: Salam ibn Miskin, quoting an old man who witnessed Abu Wa’il in a wedding feast, said: They began to play, amuse and sing. He united the support of his hand round his knees that were drawn up, and said: I heard Abdullah (ibn Mas’ud®) say: I heard the apostle of Allah (May Allah honour Him and Grant Him Peace) saying: Singing produces hypocrisy in the heart. 'Book of General Behavior (Kitab Al-Adab)' in Abu Dawud 4909.
Allah (Glory be to Him) says in Qur’an: “And of mankind is he who purchases idle talks (i.e. music, singing) to mislead (men) from the path of Allah without knowledge, and takes it (the path of Allah, or the ayah of the Qur'an) by way of mockery. For such there will be a humiliating torment (in the Hell-fire).” Qur’an.Surah Luqman 31:6
Ibn ‘Abbas said: idle talks here means singing. Mujaahid (May Allah have Mercy on Him) said: this means playing the drum (tabla). Tafseer al-Tabari, 21/40
Al-Hasan al-Basri (May Allah have Mercy on Him) said: this aayah was revealed concerning singing and musical instruments (lit. woodwind instruments).Tafseer Ibn Kathir, 3/451
Al-Sa’di (May Allah have Mercy on Him) said: this includes all manner of haraam speech, all idle talk and falsehood, and all nonsense that encourages kufr and disobedience; the words of those who say things to refute the truth and argue in support of falsehood to defeat the truth; and backbiting, slander, lies, insults and curses; the singing and musical instruments of the Shaytaan; and musical instruments which are of no spiritual or worldly benefit. Tafseer al-Sa’di, 6/150
Ibn al-Qayyim (May Allah have Mercy on Him) said: The interpretation of the Sahaabah and Taabi’in, that ‘idle talk’ refers to singing, is sufficient. This was reported with saheeh isnaads from Ibn ‘Abbas and Ibn Mas’ood. Ighaathat al-Lahfaan, 1/258-259
Allah (Glory be to Him) said: While you are Samidun as mentioned in Qur’an.Surah Najm 53:61. Sufyan Ath-Thawri (May Allah have Mercy on Him) reported that his father narrated that Ibn Abbas said about Samidun, "Singing; in Yemenite dialect `Ismid for us'. It means `Sing for us.''' Ikrimah (May Allah have Mercy on Him) said something similar. ‘Ikrimah (May Allah have Mercy on Him) said: it was narrated from Ibn ‘Abbas that al-sumood [verbal noun from saamidoon, translated here as “Wasting your (precious) lifetime in pastime and amusements (singing)”] means “singing”, in the dialect of Himyar; it might be said “Ismidi lanaa” [‘sing for us’ – from the same root as saamidoon/sumood] meaning “ghaniy” [sing]. And Messenger (May Allah honour Him and Grant Him Peace).: When they [the kuffaar] heard the Qur’an, they would sing, then this ayah was revealed. Tafseer ibn Kathir
The Messenger (May Allah honour Him and Grant Him Peace). said: “Among my ummah there will certainly be people who permit zinaa, silk, alcohol and musical instruments…” Sahih Al-Bukhari 5590, narrated as mawsool by al-Tabaraani and al-Bayhaqi, al-Silsilah al-Saheehah by al-Albaani, 91
Ibn al-Qayyim (May Allah have mercy on Him) said: This is a sahih hadeeth narrated by al-Bukhaari in his Saheeh, where he quoted it as evidence and stated that it is mu’allaq and majzoom. He said: Chapter on what was narrated concerning those who permit alcohol and call it by another name.