What is Client-side validation?
In client-side validation method, all the input validations and error recovery process is carried out on the client side i.e on the user’s browser. It can be done using JavaScript, AJAX, HTML 5 etc.
What is Server-side validation?
In server-side validation, all the input validations and error recovery process is carried out on the server side. It can be done using programming languages like C#.NET, VB.NET Shop etc.
Differences and comparison:
Client-side validation is faster than server-side because, the validation takes place on client side (on browser) and the networking time from client to server is saved.
On the other hand, server-side validation is done on the web server. Then the server renders the data into html page and sends back to the client (browser).
Server-side validation is more secure than the client-side as the user cannot see the code even he does a view-source.
