Al-hamdu lillahi rabbil 'alamin

Al-hamdu lillahi rabbil 'alamin (Arabic script الحمد لله ربّ العالمين) is the first Ayah of the first Surah of the Qur'an

Translation

The English translation of this verse is "All the praises and thanks be to Allâh, the Lord of the 'Alamîn (i.e. mankind, jinns and all that exists)".
For the complete surah " Al hamdo lillah...." translation see Surah Fatiha. In brief it is as follows:
[الْحَمْدُ للَّهِ رَبِّ الْعَـلَمِينَ ] :All praise and thanks be to Allah, the Lord of existence. [الرَّحْمَـنِ الرَّحِيمِ ] :The Most Gracious, the Most Merciful. [مَـلِكِ يَوْمِ الدِّينِ ] :The Owner of the Day of Recompense. [إِيَّاكَ نَعْبُدُ وَإِيَّاكَ نَسْتَعِينُ ] :(You (alone) we worship, and You (alone) we ask for help. [اهْدِنَا الصِّرَاطَ الْمُسْتَقِيمَ - صِرَاطَ الَّذِينَ أَنْعَمْتَ عَلَيْهِمْ غَيْرِ الْمَغْضُوبِ عَلَيْهِمْ وَلاَ الضَّآلِّينَ ] :Guide us to the straight path. The way of those on whom You have granted Your grace, not (the way) of those who earned Your anger, nor of those who went astray.

Meaning

"The meaning of (Al-Hamdu Lillah) (all praise and thanks be to Allah) is: All thanks are due purely to Allah, alone, not any of the objects that are being worshiped instead of Him, nor any of His creation. These thanks are due to Allah's innumerable favors and bounties, that only He knows the amount of. Allah's bounties include creating the tools that help the creation worship Him, the physical bodies with which they are able to implement His commands, the sustenance that He provides them in this life, and the comfortable life He has granted them, without anything or anyone compelling Him to do so. Allah also warned His creation and alerted them about the means and methods with which they can earn eternal dwelling in the residence of everlasting happiness. All thanks and praise are due to Allah for these favors from beginning to end.