What is material nature? This is also explained in Gītā as inferior prakṛti, inferior nature. The living entity is explained as the superior prakṛti. Prakṛti is always under control, whether inferior or superior. Prakṛti is female, and she is controlled by the Lord just as the activities of a wife are controlled by the husband. Prakṛti is always subordinate, predominated by the Lord, who is the predominator. The living entities and material nature are both predominated, controlled by the Supreme Lord. According to the Gītā, the living entities, although parts and parcels of the Supreme Lord, are to be considered prakṛti. This is clearly mentioned in the Seventh Chapter of Bhagavad-gītā. Apareyam itas tv anyāṁ prakṛtiṁ viddhi me parām/ jīva-bhūtām: "This material nature is My inferior prakṛti, but beyond this is another prakṛti-jīva-bhūtām, the living entity."
Material nature itself is constituted by three qualities: the mode of goodness, the mode of passion and the mode of ignorance. Above these modes there is eternal time, and by a combination of these modes of nature and under the control and purview of eternal time there are activities, which are called karma. These activities are being carried out from time immemorial, and we are suffering or enjoying the fruits of our activities. For instance, suppose I am a businessman and have worked very hard with intelligence and have amassed a great bank balance. Then I am an enjoyer. But then say I have lost all my money in business; then I am a sufferer. Similarly, in every field of life we enjoy the results of our work, or we suffer the results. This is called karma.