Soft Skills. Soft skills are any skills that are not provable or quantifiable. If Sarah Smith says she is “hardworking”, “problem solving”, has a “strong work ethic”, and “positive attitude”, the recruiter has no way of knowing whether or not that is true. Use hard skills and prove your soft skills by listing your previous accomplishments and promotions on your resume.
Your resume is arguable the single most important part of the application process. A well-organized, relevant resume will set you up to get an interview, while a poor resume will get completely lost in the sea of applicants. This is a fairly modern concern, as job postings now get thousands of online applications a day.