The U.S. immigration system is an alphabetical and numerical soup. For those who interact with the convoluted world of high-skilled employment visas, this jargon is likely lodged in their memories: I-140s, H-1Bs, H-4s, F-1s, USCIS, EADs. “We have to become our own immigration lawyers,” said Shristi Sharma, a sophomore enrolled in a dual program at the University of North Carolina-Chapel Hill and Duke University. Sharma considers herself a college student from Iowa, but to the American government, because she was born in India, she’s an H-4 dependent on her mother’s H1-B visa, mapping out how to secure an F-1, OPT and perhaps an H-1B of her own.

If you need any of these documents, you likely already know what these sentences mean. But for the rest of us, here’s a rundown:

H-1B VISA A popular visa program employers use to fill professional job positions considered to require high degrees of expertise. Around three-fourths of H-1B visas are given to Indian nationals, and roughly the same percentage are men. The visa is for three years and can be renewed for another three. During this time, the employer can sponsor the visa holder for a permanent green card. H-4 VISA This is for the dependents of H-1B visa holders, including their spouses and children.

EAD

An “employment authorization document,” it allows non-United States citizens to work. In 2015, the U.S. government allowed the H-4 spouses of H-1B visa holders to apply for EADs as they wait for their green card applications to be considered.

USCIS

The United States Citizenship and Immigration Services, per its website, “oversees lawful immigration to the United States.” Among its responsibilities, USCIS oversees the H-1B and H-4 visa processes.

FORM I-140

Visa holders use I-140s to petition USCIS for permanent residency green cards. Once the I-140 petition is filed, many begin the long wait for a green card.

AMERICA’S CHILDREN ACT

A bill introduced by Rep. Deborah Ross of North Carolina that would give foreign-born H-4 children who have lived in the United States for at least 10 years the ability to work and grant them permanent residency once they complete a degree from an institution of higher learning. The bill has several dozen cosponsors in the House and around a dozen in the Senate, a mix of Democrats and Republicans.

F-1 VISA

A student visa people can use to attend accredited schools in the United States.

OPT

“Occupational practical training.” A program that allows F-1 students to work in the United States for a period of time after they earn their degrees. OPT is one year, with students who study STEM subjects eligible for three total years of OPT.