Question Summary:
Is it compulsory for women to observe the hijab when they go outside?

Question Detail:

i have heard you say it is wajib for a women to cover face when outside. if it is not fard, then does that mean she is not obligated to cover her face or is it still an obligation?

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
 
Fardh and Wajib both imply obligation. The difference between the two is on a technical issue in the definition in which the degree of obligation in Fardh is more absolute than in Wajib.[1]
 
And Allah Ta’āla Knows Best
Muhammad Haris Siddiqui
Student Darul Iftaa
Melbourne, Australia  
Checked and Approved by,
Mufti Ebrahim Desai.