I am an Indian citizen studying in UK (Tier 4). This summer, I am planning to attend a summer school and visit an academic collaborator in US. Both are different locations and the institutes are not related. I would like to apply for visa for my US trip. I have the following few questions:
1) What type of visa I should apply for ?
2) Do I ask for a letter from both places ? With different dates ?
3) Does it require me to provide details of my accommodation at both places ?