The ability to look and apply for jobs online is a skill nearly everyone in America needs to know, experts say. But for some, it’s harder than others.

Unemployed Americans are significantly less likely than employed Americans to say they feel confident in their digital job-seeking and application skills, according to a nationally representative telephone survey of more than 2,000 Americans ages 18 and older released Thursday by the Pew Research Center.

While nearly 1 in 5 unemployed Americans say they wouldn’t find it easy to contact a potential employer via email, fewer than one in 10 people with a job say the same. The unemployed also felt significantly less confident than the employed in doing things like filling out an application online, finding jobs online and highlighting their skills on social media.

(Of course, this doesn’t necessarily mean that the unemployed have fewer digital skills than the employed, just that they are less confident in those skills. But there is research that suggests that confidence predicts success: For example, a 1995 study of accountants found that confidence predicted career success better than actual skills or training.)

This digital skills gap may help explain why many who are still unemployed can’t get jobs. “If you can’t conduct a digital job search, you probably can’t get hired,” says Lynda Spiegel, founder of Rising Star Resumes, a career coaching and resume service.

What’s more, “digital job-seeking is important even if you are doing your job search the old-fashioned way…walking around to your local stores, asking to see the manager, then making your pitch,” says professional resume writer and workforce development consultant Frank Grossman. “Chances are, unless you walk into a small independent store, the manager will say something like ‘that’s great, now go home and file our online application at the corporate website.’”

Digital skills are also key for another avenue that used to be done entirely in person: Networking. Now networking — which is still the No. 1 way to get a job with estimates that range from 40% to 80% of employed people saying they got their job in this way, according to several surveys — happens often online.

“Being a skilled digital networker is the most important skill to develop — leveraging your LinkedIn US:LNKD and Twitter TWTR, +6.08% connections is important because referrals are the way most positions are filled,” says Spiegel.

What’s more, to best leverage those connections and attract the attention of recruiters, job seekers need to make sure that their online presence is solid, including a LinkedIn profile that highlights their skills and a Facebook profile that paints them in a favorable light.

That’s thanks to the fact that more than half of companies screen candidates by looking at their social media, according to a 2015 survey by CareerBuilder. “Your digital first impression…is now just as important as your personal first impression, because so much of our careers now happen online,” says professional resume writer Susan Motley.

Job seekers also have to be able to apply for jobs smartly. Teri Coyne, the founder of career and executive coaching firm Coyne Coaching, says they have to make their résumé searchable for recruiters using the right keywords and know how to post it on job boards. “If your resume isn’t keyword optimized, it will fall into a cyber black hole, never to be read, even if you’re the perfect candidate,” says Spiegel.

That said, there are some jobs that are secured solely through word-of-mouth, without the help of digital job hunts or applications. And the unemployed can get help with their digital skills: Many local libraries offer free classes on topics like applying for jobs online and social media, and there are a number of free courses and videos on topics like these online.