What is sunnah & diffrence between hadith & sunnah

Sunnah:

The Arabic word sunnah lexically means "road" or "practice." In the language of the Prophet and the Companions it denotes the whole of licit [lawful] practices followed in the Religion [dîn], particularly the pristine (hanîf) path of Prophets, whether pertaining to belief, religious and social practice, or ethics generally speaking.

In its technical sense sunnah has three meanings. In hadith terminology it denotes any saying (qawl), action (fi'l), approval (taqrîr), or attribute (sifa), whether physical (khilqiyya) or moral (khuluqiyya) ascribed to (udîfa ila) the Prophet , whether before or after the beginning of his prophethood.1 This meaning is used in contradistinction to the Qur'an in expressions such as "Qur'an and sunnah " and applies in the usage of hadith scholars.

In the terminology of usul al-fiqh or principles of jurisprudence, sunnah denotes a saying (qawl), action (fi'l) or approval (taqrîr) related from (nuqila 'an) the Prophet or issuing (sadara) from him other than the Qur'an.

In the terminology of fiqh or jurisprudence, sunnah denotes whatever is firmly established (thabata) as called for (matlub) in the Religion on the basis of a legal proof (dalîl shar'î) but without being obligatory, the continued abandonment of which constitutes disregard (istikhfaf) of the Religion - also sin (ithm) according to some jurists - and incurs blame (lawm, 'itab, tadlîl) - also punishment ('uquba) according to some jurists.

However, some jurists have made a distinction between what they called "Emphasized sunnah " (sunnah mu'akkada) or "sunnah of Guidance" (sunnah al-huda), such as what the Prophet ordered or emphasized in word or in deed, and other types of sunnah considered less binding in their legal status, such as what they called "Non-Emphasized sunnah " (sunnah ghayr mu'akkada) or "sunnah of Habit" (sunnah al-'ada).

Sunnah is the way of life prescribed as normative for Muslims on the basis of the teachings and practices of the Islamic prophet Muhammad and interpretations of the Quran.

Difference Between Hadith and Sunnah :

Hadith and Sunnah are generally taken as synonymous terms. This is not a correct impression. The words Hadith and Sunnah have entirely different connotations, and each one holds a different status in the Shari`ah. If we assign the same meaning to both the terms, it would create a lot of complications. For a proper understanding of the science of Hadith, therefore, it is necessary to know precisely the difference between Hadith and Sunnah.  
 
Hadith :

    Hadith implies the narration of a saying, or of an act, or of an approval (Taswib) of the Prophet (sws), irrespective of whether the matter is authenticated or still disputed. The Muhaddithin (the scholars of Hadith) use the word Taqrir to express Taswib. It implies that while doing something in the presence of the Prophet (sws), a Muslim acted in a particular manner and the Prophet (sws) observed it and did not disapprove it. In this way, that person received the tacit approval of the Prophet (sws) regarding that particular action.
 
The Muhaddithin employ the term, Khabar for Hadith. A Khabar bears the possibility of being either right or wrong. In other words, the Muhaddithin believe that a Khabar may be authentic or it may be false. On this account, the Ahadith (plural of Hadith) are also termed as Zanni (presumptive or undefined).

Sunnah:
 
Literally, the word ‘Sunnah’ means ‘a clear path’, ‘busy path’, ‘trodden path’, ‘beaten path’, ‘smooth path’, etc.
 
The manner in which the Almighty deals with nations  and which holds true for all nations  as been termed in the Holy Qur’an as the Sunnah of Allah. For instance:

It was the practice [approved] of God amongst those of old that have passed away. And the Command of God is a decree determined. (33:38)

Now are they but looking for the way the ancients were dealt with? But no change will thou find in  God's way [of dealing]: No turning off wilt thou Find in God's way [of dealing]. (35:43)

In the discussion which follows, we are going to discuss the Sunnah of the Prophet (sws). This means the way of life which the Prophet (sws) taught the people in theory and practice and for which, in his capacity as a teacher of Shari`ah (Islamic Law), he laid down ideal standards of leading a life which one should meet to earn Allah's approval through complete submission to His Commandments. This assignment was a necessary corollary to his status as a Prophet and has been mentioned in the Holy Qur’an as follows:

God did confer a great favour on the Believers when He sent among them a Prophet from among themselves, rehearsing unto them the Signs of God, purifying them and instructing them in Scripture and Wisdom, while before that they had been in manifest error. (3:164)

You have indeed in the Prophet of God a beautiful pattern [of conduct] for anyone whose hope is in God and the Final Day, and who engages much in the praise of God. (33:21)

No doubt, in every sphere of life we have before us ideal examples set by the Prophet (sws) for our guidance. Whatever Commandments and rules of conduct of Islam we are supposed to know and learn have been demonstrated by him for us through actual practice.

The view point of those who do not believe in the Sunnah viz that the role of the Prophet (sws) is simply that of a courier who delivers the post is absolutely baseless and nonsensical. The Prophet (sws) is not only the Messenger who delivered the Book to humanity, but is simultaneously a Mu`allim-i-Shari`ah (teacher of the Shari’ah) and Muzakki-i-Nufus, (purifier of souls). His entire life is the highest ideal for us, and we can cast our lives in a truly righteous and Islamic mould only if we follow in his footsteps in each and every sphere of life.