What assistance and under what conditions did the United States and Great Britain provide the Soviet Union?

During World War II, the eastern front was the most important theater of military operations. After all, huge military resources were involved there, both from the USSR and from Germany. Taking into account the fact that the USSR lost the first period of the war and suffered significant losses, then among the allies there was a talk about how to support the Soviet Union. Of course, the most important support would be a military operation, but food support and support with military resources (equipment, shells, uniforms) were also an option. That is what the United States did by concluding a Lend-Lease agreement with the USSR in November 1941.