The primary function of a company credit card is to separate company and personal expenditure; which makes annual accounting for the business far simpler and straight forward. If a personal credit card is used for company expenditure, it can become difficult to isolate payments when submitting expenses during annual and VAT accounting; especially when its a small to medium sized business, with more than one employee/director (alot of payments and expenditure).
Therefore, first and foremost, a company credit card helps a business stay in control of it's expenditure with itemised specific statements. Additional cards can also be made for company employees, partners, secretaries etc. VISA and Mastercard -- the two largest credit card networks -- also have lists of business orientated services and goods that are tailored for company credit cards, and can, over time, build a credit profile for the company/business. The longer the card is used, may result in better business services being offered by the card issuer. Business credit cards can also reduce the need for the company to have petty cash on hand, and solve potential trust issues as all expenditure will be digitally stored. Useful for companies/businesses that travel abroad, as many cards provide insurance and cut down on overseas expenditure accounting paperwork.
The cons with a company credit card: they usually come with an annual fee, which can be higher than with a personal card; new companies/business may struggle to be accepted, because they have no credit history; extra services on the card may increase the annual fee; they do not always have the same level of consumer credit protection that personal credit cards have; credit limits for new businesses may make the cards ineffective for large investments.
In conclusion, company credit card are much like personal credit cards, but they do come with some drawbacks like higher fees and lack of consumer protection (UK law). On the plus-side, they help to keep accounting simplified, potential arguments / trust issues on expenditure (employees) should be minimalizsed, and the longer the card is used, the credit profile of the company should increase.