Does Tor send data over my server if I installed it? My server has a bandwidth limit so it would be bad if tor runs as a relay.
I've installed the standard tor configuration via apt-get on my Debian 8 server.
No. By default, tor
acts as a client, and opens a SOCKS5 Proxy on localhost:9050. It will not relay any traffic for the Tor Network unless you specifically set it up in the /etc/tor/torrc
file.
If one looks at the question in a more general way the answer is Yes and No.