How is the work of a recruiter? Especially where volume of applications is so high.

How does the day go like? What do they feel when they get an email from someone for some job? How do they review tons of applications? What are the deadlines that they have? How do these targets look like. How do they decide on to whom to invite for phone interview? What happens if someone rejects an offer? I am a software engineer, want to understand the mindset of a recruiter.