After Israel imposed a complete siege of the Gaza Strip in response to the deadly Oct. 7 attack by Hamas, the strip’s border crossing with Egypt became even more critical, as the only point not controlled by Israel where aid has come in and some people have been allowed out.

In typical times, the access point is alive with commercial traffic and people traveling to and from Gaza. But for two weeks after the war began, nothing passed through the crossing, which is near the southern Gazan city of Rafah, as diplomatic talks to allow people and supplies to pass were hammered out. Amid deteriorating conditions in Gaza and Israel’s persistent bombardment of the enclave, Israeli strikes have hit the crossing at least four times.

Since the border opened on Oct. 21 after negotiations between Egypt, Israel, the United States and the United Nations, aid trucks have started trickling in, though aid officials say that supplies have met only a small fraction of Gaza’s need for food, water and medicine.

On Wednesday, some foreign nationals and severely wounded Palestinians began leaving Gaza through the Rafah border crossing, the first time people were allowed to pass from Gaza to Egypt since the full siege began.

Here is what to know about the Rafah crossing:

What does it look like?

On the Palestinian side, two giant arcing structures cross each other above a short building encased in stone, with ornate metal gates blocking the way. In recent days, people hoping to leave Gaza have waited near this area.

After passing through these gates, travelers encounter another Palestinian gate where their credentials are checked. Then they usually get on a bus to travel a few hundred yards to the Egyptian part of the crossing. Private vehicles are not allowed to pass.

On the Egyptian side is a wide structure with a yellow facade. A long line of aid trucks now extends down the road, waiting to pass through to Gaza.

Why is Rafah important to Gaza?

Restrictions on the movement of people and goods to and from Gaza, imposed by both Israel and Egypt, have undermined living conditions in the enclave. Both Israel and Egypt have made entering from Gaza conditional on obtaining a permit from either government.

Egypt has at times kept the gate closed in response to security conditions. Last year, the Rafah gate was open on 245 days, according to a United Nations report, which said that more than 133,000 people had entered and 144,000 exited.

Goods such as diesel, cooking gas and construction materials typically pass through the nearby Salah a-Din gate, which started operating in 2018. Before that, household goods were mostly smuggled through underground tunnels, said Tania Hary, the executive director of Gisha, an Israeli nonprofit organization that advocates for the free movement of Palestinians.

Before the latest escalation, aid would enter Gaza through the Kerem Shalom crossing, at the corner of the enclave’s borders with Israel and Egypt, Ms. Hary said.

How has the war affected Rafah?

The United Nations High Commissioner for Human Rights says that the crossing has been damaged by Israel’s airstrikes against Hamas, the armed group that controls Gaza. After analyzing videos and satellite images, The New York Times verified several strikes that hit close to the crossing.

In past weeks, some foreign passport holders who were waiting at the border in hopes that it would open so they could leave Gaza said they had been evacuated after the crossing was struck.

American officials said they hoped that Israel would refrain from bombing the Rafah crossing area.

What is the situation now?

On Wednesday, after weeks of waiting and false starts, people began moving through the Rafah gates.

The Gazan authority for border crossings released a list of about 500 names of people who would be allowed through the southern border into Egypt on Wednesday, with more expected to follow in the coming days.

They include people with passports from Australia, Austria, Bulgaria, the Czech Republic, Finland, Indonesia, Japan and Jordan. Staff members from aid organizations including Doctors Without Borders, the International Committee of the Red Cross and UNRWA, the United Nations agency that provides aid to the Palestinians, are on the list, too.

Egypt also began taking in seriously wounded people for treatment in hospitals, the Egyptian state-owned news media reported. The Gaza authorities said that 81 such patients would cross the first day, along with family escorts.

Hundreds of aid trucks have entered Gaza through the Rafah crossing, but aid workers have said that many more are needed to relieve Gaza’s humanitarian crisis. Officials from Egypt, the United States, the European Union and the United Nations have cited stringent Israeli inspections as the main factor slowing down the process.

Israel has now agreed to allow in about 80 trucks per day, two Western diplomats briefed on the negotiations said — a greater capacity than in previous days, but still short of the 100 per day that the United Nations says Gaza needs.

The entry of fuel, which is desperately needed to generate electricity and operate vital services such as hospitals and water desalination plants, remains banned, according to the United Nations.

Reporting was contributed by Iyad Abuheweila, Abu Bakr Bashir, Monika Pronczuk, Sarah Kerr and Ainara Tiefenthäler.