Goodwill represents the difference between the purchase price and the estimated fair value of identifiable assets acquired and liabilities assumed. We are required to perform impairment tests related to our goodwill annually, which we perform during the third quarter of each fiscal year or if we identify certain events or circumstances that would more likely than not reduce the estimated fair value of the goodwill below its carrying amount. The following table represents the changes in goodwill since January 31, 2020:

Intangible assets, net, consisted of the following at April 30, 2020:

We recognized amortization expense of intangible assets in operating expense categories on the consolidated statement of operations and comprehensive loss as follows:

Future estimated amortization expense of acquired intangibles as of April 30, 2020 is as follows: