Communication over the Internet is accomplished by sending many small packets of information. Each packet is moved from its source to destination by devices called routers. Routers connect the many different smaller networks that comprise the public Internet.
When a packet goes through a router, the router decrements the packet's TTL (Time To Live) field. This is done for two purposes:
It provides a mechanism to know how many routers (i.e. hops) the packet has traversed
It prevents packets from being transmitted in an infinite loop in the event of a network configuration error. When the TTL reaches zero routers will discard the packet.
The 'ping' command shows you the received TTL after it has already gone through this decrementing. Usually the sender specifies a TTL of 128 (or 64), so if you receive it with TTL 117, that means it has travelled through 11 routers (128-117).
Can anyone explain me what's going on with TTL changes?!
Routers on the Internet usually have multiple connections to other routers. Often the routers will have multiple connections that could be used to deliver your packet. The routers job is to pick the best one. Because of changing network conditions a router may not always pick the same route each time for your packets. When this happens, your packet may end up traversing a path that involves a different number of routers. This is why you see a different TTL. This is perfectly normal. The fact there are multiple routes between destinations is indeed one reason the Internet is so resilient.
my TTL is 117 for 1 hour and just in a moment with no clue it changes to 121 and with this change my apps and games has disconnect and reconnect
In this case your TTL changing is not the cause of your problem but rather a symptom. Whatever is causing your temporarily loss of Internet connectivity is also resulting in your packets taking a different route to their destination. If the TTL is changing for all of your packets, that suggests the problem is very close to you, either in your own LAN or in your ISP's network.
