What are some important words or terms in islam

Well I'll tell you the five pillars that make up Islam.

1) Shahadah, to bear witness that there is no other God but Allah and Prophet Muhammed (peace be upon him) is his final messenger.

2) Salah which is Prayer, 5 times a day. Fajr (sunrise) Dhur (noon) Asr (afternoon) Maghrib (sunset) and Isha (evening).

3) Sawm, which is fasting, obligatory in the month of Ramadan.

4) Zakat, giving alms to the poor: charity.

5) Hajj, pilgrimage in Makkah.

Hope this helps! :)