The first major diplomatic breakthrough in the conflict follows weeks of painstaking negotiations brokered by Qatar with help from Egypt and the United States.
It is also intended to allow the delivery of desperately needed food, medicines and fuel to the 2.4 million civilians trapped in Gaza in increasingly dire conditions.
The deal is crafted to take effect in stages that the mediators hope can be extended and broadened. Here is what we know so far:
- Mediator Qatar to announce start
"The starting time of the pause will be announced within the next 24 hours and last for four days, subject to extension," Qatar's foreign ministry said.
The process could begin Thursday at 10am (0800 GMT), according to media reports.
- Further exchange possible
In a first step, 50 hostages and 150 Palestinian prisoners are set to be released during the four-day pause in fighting.
If successful, a second phase could see 150 more Palestinian prisoners freed in exchange for another 50 hostages during an extended truce, the Israeli government said.
While hostages are moved, Israeli reconnaissance of Gaza would be put on temporary hold, Qatar's foreign ministry spokesman said.
- Who will be freed?
Under the agreement, 50 women and children held hostage in the Gaza Strip would be released in exchange for Palestinians, according to Hamas.
A senior US official said three Americans, including three-year-old Abigail Mor Idan, were among them.
Qatar said no military prisoners were among those to be released.
Israel published the names of 300 Palestinian detainees who could be freed -- the vast majority of them teenage boys.
Of those on the list, 49 are identified as Hamas members, 60 as belonging to Fatah, the party which leads the Palestinian Authority in the occupied West Bank, and 17 as being affiliated with the leftist Popular Front for the Liberation of Palestine (PFLP).
- Aid 'surge' planned
"The European Commission will do its utmost to use this pause for a humanitarian surge to Gaza," she said.
Qatar said the deal would include "the entry of a larger number of humanitarian convoys and relief aid, including fuel designated for humanitarian needs".
Senior Hamas official Taher al-Nunu said at least 200-300 aid trucks would enter as part of the truce, including eight carrying fuel and gas.
- Israel says war not over
In a statement, the Israeli government pledged to "continue the war in order to return home all of the hostages, complete the elimination of Hamas and ensure that there will be no new threat to the State of Israel from Gaza".
Ahead of the crunch meeting which approved the deal, hawkish Defence Minister Yoav Gallant said he had won assurances it would not spell the end of the war.
"Immediately after we have exhausted this phase" he said, security operations would "continue in full force".