conventional bank

Dear scholars, As-Salamu `alaykum. I would like to know, in your opinion, what the difference is between conventional and Islamic bonds.Also, I would like to know your opinion regarding the definition of riba in Islam and interest rates in conventional banks. Thanks.

I recently graduated in the field of marketing. My father insists that I work for finance and he wants me to work for an investment bank in the USA to gain experience in the field of investment. I know this is a technical field and so I want to know if it is permissible to work for an investment bank or not and are there particular areas in which I could work for this bank? If not are there other investment institutions whose operations are lawful in the USA?