Making it simple, localhost as a web address connects to your local machine, where in this case you have Apache installed as web server. The second part, :8080, means connect to port 8080 of that web address. If you don't specify it, your web browser will connect to the default webserver port, which is port 80.
Employer Identification Number. The Employer Identification Number (EIN), also known as the Federal Employer Identification Number (FEIN) or the Federal Tax Identification Number, is a unique nine-digit number assigned by the Internal Revenue Service (IRS) to business entities operating in the United States for the purposes of identification.
This article is about identification numbers used in the US tax system. For taxpayer identification numbers used in other countries, see National identification number. A Taxpayer Identification Number (TIN) is an identifying number used for tax purposes in the United States. It is also known as a Tax Identification Number or Federal Taxpayer Identification Number. A TIN may be assigned by the Social Security Administration or by the Internal Revenue Service (IRS).