The term capital investment has two usages in business. First, capital investment refers to money used by a business to purchase fixed assets, such as land, machinery, or buildings.1

Secondly, capital investment refers to money invested in a business with the understanding that the money will be used to purchase fixed assets, rather than used to cover the business’s day-to-day operating expenses.2

 For example, to purchase additional capital assets, a growing business may need to seek a capital investment in the form of debt financing from a financial institution or equity financing from angel investors or venture capitalists.

Objectives of Capital Investment
There are typically three main reasons for a business to make capital investments:

To acquire additional capital assets for expansion, enabling the business to, for example, increase unit production, create new products, or add value
To take advantage of new technology or advancements in equipment or machinery to increase efficiency and reduce costs1
To replace existing assets that have reached end-of-life (a high-mileage delivery vehicle or an aging laptop computer, for example)
Capital Investment and the Economy
Capital investment is considered to be a very important measure of the health of the economy. When businesses are making capital investments it means they are confident in the future and intend to grow their businesses by improving existing productive capacity. On the other hand, recessions are normally associated with reductions in capital investment by businesses.

Capital-Intensive Businesses
Capital intensive businesses require a lot of investment in areas such as labor, facilities, equipment, along with repair and upgrades.3

Rail companies are notoriously capital intensive, requiring regular investments in line upgrades, rolling stock, and facilities. For example, in 2016 CN Rail outlined $2.9 billion in capital improvements for the year, which included $1.5 billion on track infrastructure such as replacement of rail, ties, and other track materials, bridge improvement, and branch line upgrades. Other investments were related to improving traffic volume, fuel efficiency, and service.4

Source: https://www.thebalancesmb.com/capital-investment-2948114