-=head2 What data can be put into an RRD ?
-
-You name it, it will probably fit. You should be able to measure some value
-at several points in time and provide this information to RRDtool. If you
-can do this, RRDtool will be able to store it. The values need to be
-numerical but don't have to be, as opposed to MRTG, integers.
-
-Many examples talk about SNMP which is an acronym for
-Simple Network Management Protocol. "Simple" refers to the protocol --
-it does not mean it is simple to manage or monitor a network. After working your
-way through this document, you should know enough to be able to understand
-what people are talking about. For now, just realize that SNMP is a way to
-ask devices for the values of counters they keep.
-It is the value from those counters that are kept in the RRD.
-
-=head2 What can I do with this tool ?
-
-RRDtool originated from MRTG (Multi Router Traffic Grapher). MRTG started
-as a tiny little script for graphing the use of a connection
-to the Internet. MRTG evolved into a tool for graphing other data sources
-including temperature, speed, voltage, number of printouts and
-the like. Most likely you will start to use the RRDtool to store
-and process data collected via SNMP. The data will most likely be bytes
-(or bits) transfered from and to a network or a computer.
-RRDtool lets you create a database, store data in it, retrieve that data
-and create graphs in PNG format for display on a web browser. Those PNG
-images are dependent on the data you collected and could be, for instance,
-an overview of the average network usage, or the peaks that occurred.
-It can also be used to display tidal waves, solar radiation, power
-consumption, number of visitors at an exhibition, noise levels near an
-airport, temperature on your favorite holiday location, temperature in the
-fridge and whatever you imagination can come up with. You need a sensor to
-measure the data and be able to feed the numbers to RRDtool.
-
-=head2 What if I still have problems after reading this document ?
+=head2 What data can be put into an RRD?
+
+You name it, it will probably fit as long as it is some sort of
+time-series data. This means you have to be able to measure some value
+at several points in time and provide this information to RRDtool. If
+you can do this, RRDtool will be able to store it. The values must be
+numerical but don't have to be integers, as is the case with MRTG (the
+next section will give more details on this more specialized application).
+
+Many examples below talk about SNMP which is an acronym for Simple Network
+Management Protocol. "Simple" refers to the protocol. It does not
+mean it is simple to manage or monitor a network. After working your
+way through this document, you should know enough to be able to
+understand what people are talking about. For now, just realize that
+SNMP can be used to query devices for the values of counters they keep. It
+is the value from those counters that we want to store in the RRD.
+
+=head2 What can I do with this tool?
+
+RRDtool originated from MRTG (Multi Router Traffic Grapher). MRTG
+started as a tiny little script for graphing the use of a university's
+connection to the Internet. MRTG was later (ab-)used as a tool for
+graphing other data sources including temperature, speed, voltage,
+number of printouts and the like.
+
+Most likely you will start to use RRDtool to store and process data
+collected via SNMP. The data will most likely be bytes (or bits)
+transferred from and to a network or a computer. But it can also be
+used to display tidal waves, solar radiation, power consumption,
+number of visitors at an exhibition, noise levels near an airport,
+temperature on your favorite holiday location, temperature in the
+fridge and whatever your imagination can come up with.
+
+You only need a sensor to measure the data and be able to feed the
+numbers into RRDtool. RRDtool then lets you create a database, store
+data in it, retrieve that data and create graphs in PNG format for
+display on a web browser. Those PNG images are dependent on the data
+you collected and could be, for instance, an overview of the average
+network usage, or the peaks that occurred.
+
+=head2 What if I still have problems after reading this document?