Definite-Lived Intangible Assets, Net
 3 Months Ended
Apr. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]  
Definite-Lived Intangible Assets, Net Definite-Lived Intangible Assets, Net
As of the periods presented, definite-lived intangible assets consisted of the following (amounts in tables in millions):
April 30, 2021
Weighted-Average Useful Lives
(in years)		Gross Carrying AmountAccumulated AmortizationNet Book Value
Purchased technology5.3$958 $(505)$453 
Customer relationships and customer lists11.5726 (305)421 
Trademarks and tradenames7.6132 (83)49 
Other2.021 (18)3 
Total definite-lived intangible assets$1,837 $(911)$926 
January 29, 2021
Weighted-Average Useful Lives
(in years)		Gross Carrying AmountAccumulated AmortizationNet Book Value
Purchased technology5.3$948 $(462)$486 
Customer relationships and customer lists11.4727 (281)446 
Trademarks and tradenames7.6132 (78)54 
Other2.021 (14)7 
Total definite-lived intangible assets$1,828 $(835)$993 
Amortization expense on definite-lived intangible assets was $77 million and $80 million during the three months ended April 30, 2021 and May 1, 2020, respectively.
Based on intangible assets recorded as of April 30, 2021 and assuming no subsequent additions, dispositions or impairment of underlying assets, the remaining estimated annual amortization expense over the next five fiscal years and thereafter is expected to be as follows (table in millions):
Remainder of 2022$224 
2023251 
2024199 
2025106 
202666 
Thereafter80 
Total$926