Laptop computers come with several input and output ports for various applications, and usually come from the manufacturer with components and programming to support those connectors. However, with so many types available for Internet connections and peripheral devices, no laptop can possibly have all connectors. If your laptop doesn't have an HDMI port, you may be able to install a peripheral device for HDMI connections.
Since laptops have so many uses, manufacturers install different components and programs for certain applications. A laptop set up for student use will have less costly components and concentrate on word processing and Internet connections. One designed for executive or sales presentations will have a more elaborate graphics card and video outputs, and probably an HDMI port built into the chassis. Even without such a port, in many cases, you can add an HDMI connection.
A laptop set up for video presentations without an HDMI port may have other video options. The simplest is a single yellow RCA "push-in" jack for composite video that can connect to most television sets or video recorders. An S-video connection has a round, four-pin connector, and a component video connection has three RCA jacks colour-coded green for the Y signal, red for the Cr and blue for the Cb. A VGA output has a 15-pin connector and a DVI connector has a 24-pin connector. Any of these can connect to an HDMI converter or adaptor.
If your laptop has any video connection at all, it can connect to an HDMI converter for any video format. One type of converter changes analogue formats into HDMI and another type changes HDMI into analogue. With a converter, you can change the analogue video inputs or outputs of your laptop to HDMI by connecting the analogue side of the converter to your laptop and the HDMI side to the appropriate device. If your laptop has a digital video interface port, you can use a DVI to HDMI adaptor cable that does not need electronic conversion.
If your laptop doesn't have any video connections at all, but has a free USB port, you can connect an external video card with an HDMI port to it. However, with so many different laptops and HDMI video cards available, the card must match your computer for its operating system, processor type and speed, vacant hard drive space and RAM capacity. Check the specifications of the video card and compare them to your laptop to ensure they are compatible.