What is "industrial capitalism"? What's the difference between "industrial capitalism" and "agrarian capitalism" and "mercantilism" and the "industrial revolution" and the 20th century ideas of "Keynesianism"?

Is agrarian capitalism- plantations, industrial capitalism- the exploitation of women working in clothing factories?
Industrial capitalism, characterized by its use of heavy machinery and a much more pronounced division of labor.  It is a system  whereby industry and resources are owned by few for profit. In this capitalist system means of production were privately owned.  Its is marked by the rise of monopolies and trusts dominating industry and other aspects of society. Often used to describe the economy of the late 19th and early 20th century.

Agrarian capitalism refers to the description of agricultural economy. It is centered upon the production, consumption, trade, and sale of agricultural commodities, including plants and livestock, is rural rather than urban-based. 

mercantilism was based on the idea that a nation's wealth and power were best served by increasing exports and limit imports. 

The Industrial Revolution began in the 18th century, when agricultural societies became more industrialized and urban.  During this period society moved form primary Agrarian capitalism  to Industrial capitalism.   

An agrarian society Wealth comes from the land. Industrial society refers to a society driven by the use of technology to enable mass production, supporting a large population with a high capacity for division of labor. Industrial society is characterized by the use of external energy sources, such as fossil fuels, to increase the rate and scale of production.

Mercantilism developing during 16th century came about  as governments created incentives to only buy its own countries goods especially among colonies.   However, these views changed with the introduction of capitalistic beliefs and value to the late 1700s.    The industrial revolution came about because industrialization required significant work and investment from individuals and not necessarily the government. 

Keynesianism - the theory made an argument for active government intervention during recessions, leveraging tools of monetary and fiscal policy to restore confidence, boost output, and smooth the ups-and-downs of the business cycle.  

To answer your question agrarian capitalism does include the use of plantations.  

During the industrial revolution women entered the workforce in textile mills and coal mines in large numbers.  Women and children often worked in the factories and mines in order to help pay for the families cost of living.   Women were not valued the same as men in the workplace, and were often paid much less than men.  However, during this time the early feminist movements started as women began to organize and protest for more equality in society.

https://www.historycrunch.com/role-of-women-in-the-industrial-revolution.html#/