Explain Stock-based compensation expense

(In millions) 2020 2019 $ $ June 30, Deferred Income Tax Assets Stock-based compensation expense Accruals, reserves, and other expenses Loss and credit carryforwards Depreciation and amortization Leasing liabilities Unearned revenue Other 461 2,721 865 6,361 3,025 1,553 354 406 2,287 3,518 7,046 1,594 475 367 Deferred income tax assets 15,340 15,693