It's merely a description of your processor. It's an Intel Pentium 4 Dual Core manufactured by IBM. It's speed is 2800Mhz or 2.8Ghz.
For example, you can see that my processor is labeled Intel Core 2 Duo 2.93Ghz T9800
i.e.
Vendor: Intel
Manufacturer: IBM
Speed: 2930Mhz
Cores: Two
Model: T9800 (Notebook 65W, 2.93Ghz)
Even though you have an IBM computer, the individual components are of different vendors. Intel, AMD, NVIDIA, etc. IBM actually makes most of the processors still, but it's usually not noted on anything inside the computer. AMD and Intel are both processor vendors. NVIDIA and ATI are graphics card vendors manufactured by various companies.
You have to keep in mind that there are many different companies involved in making your computer. You'll likely have a pre-made computer made by a company such as IBM, Dell, Gateway, etc. Then the internal parts are manufactured by one company like IBM or various graphics card companies. However, those companies simply pay a licensing fee to make and sell these parts, they were actually invented/made by another company (Intel/AMD/NVIDIA).
A good example is your motherboard and cpu.
The CPU is manufactured (put together) by a company such as IBM.
It was invented by a company such as Intel.
Your motherboard is manufacturered by a comapny such as Gigabyte.
However, it contains a chipset that was invented by a company such as NVIDIA.
It might contain more components which were invented by even more companies.