Short answers, pulled from the story.
Decree 900, also known as the Agrarian Reform Law, was a Guatemalan land-reform law passed on the 17th of June 1952 under President Jacobo Árbenz Guzmán. It redistributed uncultivated land from large estates to landless peasants, compensating former owners with government bonds. The law affected approximately 1,700 estates and transferred land to about 500,000 people, one-sixth of Guatemala's population.
Decree 900 was passed to address extreme land inequality: 2% of Guatemala's population controlled 72% of all arable land, and only 12% of that land was being farmed. Árbenz aimed to shift Guatemala from what he called a pseudo-feudal economy to a capitalist one by distributing unused land to landless peasants and increasing agricultural output.
Under Decree 900, Guatemala expropriated approximately 234,000 acres of uncultivated land from the United Fruit Company, compensating the company with $627,572 in bonds. United Fruit, which held 550,000 acres representing 42% of Guatemala's arable land, disputed the valuation and lobbied the U.S. government for intervention, contributing directly to the 1954 CIA-backed coup.
Decree 900 was repealed after the June 1954 coup that overthrew Árbenz, orchestrated by the CIA through Operation PBSuccess with military forces led by Carlos Castillo Armas. Armas became president on the 8th of July 1954 and reversed 95% of all land redistributions, restored all land to United Fruit, and destroyed government documents relating to the law.
Decree 900 was in force for eighteen months, from its signing on the 17th of June 1952 until its repeal following the coup in July 1954. In that period, 1,400,000 acres were redistributed to 100,000 families, and a National Agrarian Bank disbursed millions in loans with a repayment rate of around 90% by July 1954.
The Communist Party of Guatemala (PGT) supported Árbenz politically and its leaders were among his personal friends. PGT members helped draft the legislation and proposed the Local Agrarian Committees that administered land redistribution at the community level. Árbenz accepted some PGT proposals but rejected others, including a mandate for producer cooperatives.