It’s to let people who don’t know about them, Know what they have done in their careers. Its called Promotion

Press kit

A press kit, often referred to as a media kit in business environments, is a pre-packaged set of promotional materials of a person, company, or organization distributed to members of the media for promotional use. They are often distributed to announce a release or for a news conference.

Uses

Press kits are commonly used for:

    Product launches
    New company launch
    Mergers and acquisitions
    News conferences
    Large events / Industry trade shows

Common components

    Backgrounder with historical information on the company or individual.
    Fact sheet listing specific features, statistics, or benefits.
    Biographies of key executives, individuals, artists, etc.
    Past press coverage
    Photos or other images (high resolution) of key executives, logos, products, etc.
    A press release detailing the current news the media kit is sent in reference to
    Media contact information (usually of a public relations department or spokesperson)
    A CD, DVD, software title, video, etc. as appropriate for the sender of the release
    Collateral advertising material, such as: postcard, flier, newspaper ad, etc.

Band press kits

Press kits are a common promotional tool used by musicians when launching a new album. Band press kits often have their own unique set of components, including:[citation needed]

    Band biography / History of the band
    CD
    Color photos (many corporate photos are done in black and white for newspaper print purposes)
    Contact information for the band’s label, manager, publicist, or other representative
    Discography (all previous albums released by the band)
    Equipment list (if the kit is being sent to live music venue)

Electronic press kit (EPK)

An electronic press kit (EPK) is a press kit equivalent in electronic form. An EPK usually takes the form of a website or e-mail, though they are also known to exist in CD and DVD form. The first known EPK, as we know it today, premiered live on the web on January 8, 1995 and was invented and given the exact name electronic press kit or EPK by Andre Gray, the inventor of online music sales certifications and winner of The Johannes Gutenberg Inventor Prize. Gray’s EPK featured a bio, audio clips, videos, photos, press, set list, basic technical requirements, and a calendar and featured R&B singer and songwriter Aaron Hall as the first artist ever to have an EPK created on their behalf.
Distribution formats

An electronic press kit can be distributed via the following media:

    CD
    DVD
    Video or audio cassette
    The Internet (e.g. E-mail, WWW, newsgroups, etc.)
    USB flash drive

Electronic press kits are also available on corporate websites, where kits are offered in PDF format.
Contents

Contents depend on the industry and target audience. For instance, an EPK in the music industry might contain the following:

    Biography
    Music clips
    High resolution press photos
    Tour dates
    Promotional videos
    Offline website or website links
    Press reviews and interviews
    “RIYL” or “recommended if you like” list (list of artists in similar styles or genres)
    Contact information
    High resolution photos or images of key executives, the company logo, products, etc.