@eng.hussain For that number of students, that is a major project. You will want to bring in someone who really knows networking as you will need to have a lot of pre-project work done like site mapping for interference. You will need to also look at who all will be connecting, how they need to be isolated from each other, indoor and outdoor AP's, cabling and backend switches, and VLANS. Sorry, not a good answer but in all honesty, there is a whole lot of planning and decisions that need to be made first.

@Merryworks 

Thank you for answering my question.
You said it, it's a big idea and it needs a specialist.
But now I had a second idea to start with a small area that one wifi device would suffice to cover and be connected via an Ethernet cable to my server, and this Wi-Fi device has the ability to work with a fixed IP address with a domain name system where students can access this domain through their browsers So that they can use the web application that I provide for them in this server and the number of students does not exceed 100 students only.
What is the type of WiFi device that allows this number of students (or more) to communicate?
Note that I have fully applied this idea with one of the types of routers from MikroTech.
But the problem is that this device does not exceed 25 people who can connect to it.

@Merryworks Thank you very much. You helped me a lot

Hi @eng.hussain,

I'm not sure what country you are in, but ideally the new EAP265 (or EAP245V3) would be ideal, in concert with managed high power POE switches and the new OC300.  I totally agree that hiring an expert would be appropriate for a project of this scale.  But, you can certainly setup a small test case for $<1000.

Given that many total users, the first thing to consider is the space plan / layout of the users.  How many buildings, floors, rooms, classrooms, lecture halls, etc.?  What is the maximum number of wireless users that will be in each space?  What kinds of devices will students have?  (e.g. all they all/mostly modern devices that support 5.8GHz 802.11ac (aka Wifi5) or newer)?

The EAP245 & 265 are physically identical, but, theoretically, the 265 has different firmware than enables more simultaneous users.  Though I've not seen any data/tests to actually prove this is true.  Even the EAP225V3's which I have can easily support 40-50 users since, in most cases, most of the devices are idle at any given time.  But, if you have 5 or 10 clients actively downloading/streaming large files (HD/4K content) this will certainly impact the speeds others on that AP are seeing during the duration of the download/upload.

Generally speaking for large spaces (conference room, lecture hall) it's much better to have multiple "mid-tier" products than to try and rely on one or two higher-end products.  But for this to work effectively, you also need to carefully consider your available RF spectrum (do a wireless survey, think about BW per radio, manage channel allocation), and consider the AP placement, antenna radiation profile, and transmit power.

Similarly, while potentially less convenient, it's best to keep "fixed" devices off of the wireless whenever possible.  For example, having ethernet at the teachers podium/desk.  Using ethernet in dorm rooms for desks and especially TV areas when folks stream content (Youtube, Netflix, etc.).

Keeping as much "recreational" video, music, and VOIP streaming off of the wireless helps ensure capacity is available for actual mobile work.

Finally, if you haven't checked it out yet, look into the Omada/SDN software -- it's free.  You can run this on a PC/workstation/server but the appliances are so much nicer since it's useful to leave the software running all of the time.  As you are selecting new components (AP, Switch, Gateway, etc.)  Be sure to select devices which are supported by the new SDN environment.  This software lets you centrally manage and monitor all of the connected devices (AP, Switch, Gateway) letting you see the status of the network in the office and from home.

-Jonathan